EEVblog #596 - World's Cheapest Soldering Station - Yihua 936 - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2014, 01:18:27 pm
content: Dave takes a look at the world's cheapest temperature controlled soldering station, the $16 Hakko 936 knockoff Yihua 936 from Hobby King.How does it compare to the older genuine Hakko 926?Also, thermal capacity comparison testing is done on those two irons plus the high thermal capacity JBC.Sagan also gives his verdict.http://en.yihuaxin.com/about.htmlHakko 936 Schematic:http://dalincom.ru/datasheet/HAKKO_936_schematic.pdf!Private video

author: dr.diesel
author_rank: Super Contributor
timestamp: March 29, 2014, 01:43:36 pm
content: Wow, man that is really cheap. I don't see how you can afford projects/components if that's the best iron your budget allows.Not to mention it won't last and you'll have to buy another one.

author: HighVoltage
author_rank: Super Contributor
timestamp: March 29, 2014, 01:58:48 pm
content: I feel sorry for those who have to work with this kind of soldering iron.In Germany, we only had good quality brand names to select from in the past.But lately there is a trend to see all these low end irons around.They probably use one of these Yihua 936 in their own production line of Yihua 936's.

author: nihilism
author_rank: Regular Contributor
timestamp: March 29, 2014, 02:05:53 pm
content: looks like the pcb is "washed" after wave soldering, in the river it seems.

author: bxs
author_rank: Regular Contributor
timestamp: March 29, 2014, 02:09:18 pm
content: Not so long ago I also bought a 936 clone, it cost me several times more that this one, but is probably the same or worse qualityI will have to wait so see the video since my net connection are very slow and unstable, I will have to download the video first and then see itI only bought a clone because I couldn't find in Europe a OK iron for a OK price, the ones I found were several times more expensive than is US, but I need 220V and from Europe, because of the import duty and taxesBut, I used the station a bit, the temperature accuracy is quite good and works quite well so far

author: free_electron
author_rank: Super Contributor
timestamp: March 29, 2014, 02:13:53 pm
content: Soldered earth is allowed provided the wire is looped back (not just poked through the hole, but bent back 180 degrees.Now a big worry is the esd stuff . Zero ohms from tip to mains ground ? That should read 1 meg !

author: all_repair
author_rank: Frequent Contributor
timestamp: March 29, 2014, 02:15:58 pm
content: I used to buy an extra original set for commonly used tool, buy they hardly spoil. So lately I am buying these Chinese clones as a hot stand in the event the real machine breakdown and before the original is repaired or is replaced by another original. I don't know is this a right strategy but keeping original as hot stand-in is very costly and wasteful if you have quite a few types to provide, and also they may go missing along the way. Good things about these clones, i can use the original tips, heating element, spare parts.

author: ablacon64
author_rank: Frequent Contributor
timestamp: March 29, 2014, 02:31:55 pm
content: In Brazil a lot of technicians use this kind of station just because good quality soldering stations are quite expensive around here. I have one but it's taken as "top quality" in Brazil, it's made by Hikary. But I guess despite of its cost being much more than this one, it's the same crap.

author: BravoV
author_rank: Super Contributor
timestamp: March 29, 2014, 02:36:14 pm
content: Dave, about the photo of genuine Hakko 907 iron used in 936 station, its here at your own forum.Made a comparison between the fake vs genuine Hakko 907 soldering iron ->Hakko 936 ceramic heater A1321 vs fake comparison, actually the fake iron is good part source for 2nd iron if non critical part from the genuine one is getting rusted or old aged, of course after modded with genuine heater element and the genuine Hakko tip which is the secret sauce. The genuine Hakko element it self cost $17 locally here.Also made a comparison on the tip differences ->Genuine vs fake Hakko solder tip comparison

author: sleemanj
author_rank: Super Contributor
timestamp: March 29, 2014, 02:59:44 pm
content: The pcb assembly does look like crap I'll give you that, but apart from that, I think many a happy hour could be spent by the hobbiest with one and I doubt they would ever think "gee, if only I had a real one". How often do you really need to attack a big heatsink.Although I'd replace the handle with one that has a silicone cable.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 29, 2014, 03:02:04 pm
content: You could easily have checked the authenticity of the mains cable printed cross-section using the 4-wire ohms on your Agilent DMM

author: bxs
author_rank: Regular Contributor
timestamp: March 29, 2014, 03:10:39 pm
content: Ok, I saw the video, my clone's pcb have a better finish quality, and the heater led have a stable ON/OFF, the Temp Pot feels really good and a proper earth connection, the rest? probably the same.If we look for the big picture it just switch the heater element ON/OFF based on the set temp and heater temp

author: ivan747
author_rank: Super Contributor
timestamp: March 29, 2014, 03:21:35 pm
content: My first thought when I saw the video on my inbox:

author: SeanB
author_rank: Super Contributor
timestamp: March 29, 2014, 03:58:00 pm
content: Earth fails for more than one reason. Must be connected to case using a shake proof washer so it cannot come loose from vibration. Must be done with a dedicated screw not used for any other purpose like holding down the transformer or closing the case. Must be either a crimped connection or a screw connector, not a soldered connection that can creep with time and come loose with heat. If multiple earth conductors are attached each must have it's own lug and no daisy chaining of earth wires inside allowed. All accessible metal parts must be earth bonded, including cases of potentiometers, unless they are mounted internally so only a plastic shaft protrudes from the case.

author: ohmineer
author_rank: Contributor
timestamp: March 29, 2014, 04:12:03 pm
content: Quote from: free_electron on March 29, 2014, 02:13:53 pmIs that correct? If so, I was completely wrong.In the past, I saved this note as reference to test my soldering stationshttp://www.esda.org/documents/openforumhandtoolsprass08.pdf.Maybe it is time to trash it.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 29, 2014, 04:23:17 pm
content: That pcb is literally crusty, is that just flux residueI wonder if this is as crap:http://www.rapidonline.com/Tools-Equipment/48W-Adjustable-Temperature-Analogue-Soldering-Station-525406

author: Tuppe
author_rank: Contributor
timestamp: March 29, 2014, 04:29:42 pm
content: I have Aoyue version of this knock-off. It's way different in design. It was about 40$ shipped.There are crimped connectors, actual metal stand, replaceable fuse, LM324 comparator circuit & optocoupler etc.Transformer is way smaller though.But the problem is that it broke after 2 weeks. I'm not even kidding.But I bought it from reputable seller, Wiltec. They politely just sent me a new piece for warranty without even asking for it.And it broke too. Not even kidding. I'm not surprised though, the PCB looks like it was recovered from a WW2 submarine. Even the IC leads are totally covered with green corrosion stuff. Although you can't see it in the image, the PCB quality in the other one is OK.The first one didn't heat up anymore, and the second one blew the fuses IIRC because of the soldering handle element.I was able to combine 1 working unit out of the 2, and by switching the heating elements(both units came with a spare one) I got the both handles working. Ironically I had to get another 5$ solder iron to fix these damn things.I have no idea what is wrong with the another one, I can't get my head around analog circuits. The LM314 is only getting 1.8V for some reason in the faulty one. 5V in the working one.If anyone has some ideas what I could try. I have working unit that I can compare voltages to.Anyways, I can recommend Wiltec as a store for sure(they sell these multiple variations of Aoyue stations), but you might want to go with older Hakko's if you can get one for 100-150$.?I looked for the real deal, but I wasn't able to get one in Finland shipped for under 150$.There are multiple variations of this thing:936 - 35W analog (30€)936A - 60W analog (80€)937 - 50W digital with dial (55€)937+ - 50W digital with buttons (60€)950 - 60W SMD tweezer handle (60€)3210 - 70W, digital (70€)Here's images of the Aoyue 936, the cheapest of them all:I wouldn't be too conserned about the quality of the more priced ones. They could've cut way costs in detail with this if they wanted to. They also seem to incorporate some of their own design in it too. For the price it's okay. It has worked well since I repaired it. If you put a price on your time, this iron would've cost me like 150$.

author: Monkeh
author_rank: Super Contributor
timestamp: March 29, 2014, 04:29:51 pm
content: Quote from: electronics man on March 29, 2014, 04:23:17 pmWorse, those aren't even temperature controlled.

author: Rufus
author_rank: Super Contributor
timestamp: March 29, 2014, 05:06:34 pm
content: The talk of high capacity irons is confusing. The JBC cartridges have very low thermal capacity which is why they heat up quickly. JBC calls their stubby bits with relatively fatter metal between the heater element and tip 'high thermal efficiency'.The real issues are how much power can be put into the heater element and the thermal resistance between the heater, the sensor, and the tip.High thermal resistance between the heater and tip means you need to run the heater at a higher temperature to get the same temperature at the tip for a given thermal load.A good way of testing is to get some aluminium PCB with a large pad and mount it on a big aluminium heatsink with some thermal compound. A large blob of solder on the pad is going to pull about as much heat as is possible out of the tip. At a given set temperature how much power the iron manages to put into the blob is a good measure of overall thermal performance - just measuring mains input power gives you an easy indication (subject to iron electrical efficiency considerations).

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 29, 2014, 05:29:48 pm
content: Quote from: Monkeh on March 29, 2014, 04:29:51 pmyes - those are terrible pieces of junk - it's just an input power control, so when set to a good temp for soldering, they overheat when idle and trash the tip.

author: linux-works
author_rank: Super Contributor
timestamp: March 29, 2014, 05:48:37 pm
content: rod elliott has a good write-up on grounding to the chassis:http://sound.westhost.com/earthing.htmthat seems to make sense even though it looks like a lot of extra 'rules' to follow.

author: synapsis
author_rank: Regular Contributor
timestamp: March 29, 2014, 08:22:27 pm
content: I have a Hakko 937 that works, but looks like the case was hit by a truck. I wonder if the Yihua 936 case would fit...

author: SeanB
author_rank: Super Contributor
timestamp: March 29, 2014, 08:25:54 pm
content: Probably. Was looking, but the cheapest now is $40 with free postage. The Dave Jones Effect strikes again.

author: Monkeh
author_rank: Super Contributor
timestamp: March 29, 2014, 08:27:27 pm
content: Quote from: SeanB on March 29, 2014, 08:25:54 pmGo to Hobbyking.. They have never been that cheap on eBay.

author: mariush
author_rank: Super Contributor
timestamp: March 29, 2014, 09:03:18 pm
content: It's 16-18$ but there's nothing stocked in the European warehouse for example. Shipping is between 1$5 and $79, depending on choices.. and the cheapest depends if the item is in Europe warehouse which is not the case.It is a good deal if you buy 5-10 of them, in which case the shipping fees would probably be good.

author: Monkeh
author_rank: Super Contributor
timestamp: March 29, 2014, 09:16:42 pm
content: Quote from: mariush on March 29, 2014, 09:03:18 pmThey do come back into stock. Shipping from a local warehouse is not too expensive.

author: senso
author_rank: Frequent Contributor
timestamp: March 29, 2014, 09:29:02 pm
content: And if you clean your cookies and leave the Hobbyking page open it will do a one time offer of 14$, thats just above 10€, 10€ was how much a tip for my non temperature controlled JBC costed.

author: EEVblog
author_rank: Unknown
timestamp: March 29, 2014, 09:42:28 pm
content: Quote from: bxs on March 29, 2014, 03:10:39 pmIt might "feel OK", but the Hakko uses a proper ALPS brand, the cheapie will use whatever rubbish is on the shelf this week.

author: don.r
author_rank: Frequent Contributor
timestamp: March 30, 2014, 12:33:50 am
content: I have an Atten version of this. The ONLY difference is that the transformer was not grounded and the ground wire went directly to the PCB. It was hanging on by two or three strands. Given that a Hakko 888D goes for less than $100 + shipping on fleabay, I could never recommend anyone go for this. Buy a mains plug iron for a first/backup and then save your money for a proper iron. Really.EDIT: Ooops! One other difference. The transformer also had a 14-0-14 secondary with connector that was unused. I guess they got a cheap job lot that day.

author: Monkeh
author_rank: Super Contributor
timestamp: March 30, 2014, 12:43:36 am
content: Quote from: don.r on March 30, 2014, 12:33:50 amLegit ones for the majority of the planet don't, no.

author: sleemanj
author_rank: Super Contributor
timestamp: March 30, 2014, 01:01:16 am
content: Quote from: don.r on March 30, 2014, 12:33:50 amThere are lots of counterfeit copies of the 888. The fake ones don't have a microcontroller in them, purely analog control, while the real ones have a micro. You won't know unless you open it up, they are probably using the same mouldings, may well be from the same factory working a "ghost shift".See this thread:https://www.eevblog.com/forum/reviews/too-good-to-be-true-(220v-hakko-fx-888-replica)/I wouldn't be at all surprised if the 888D was also heavily counterfeited

author: don.r
author_rank: Frequent Contributor
timestamp: March 30, 2014, 01:15:20 am
content: Quote from: Monkeh on March 30, 2014, 12:43:36 amAuthorized Distributor (if that means anything, not sure)http://www.ebay.ca/itm/Hakko-FX888D-23BY-Digital-Soldering-Station-FX-888D-/281104049653?pt=LH_DefaultDomain_0&hash=item41731b65f5&_uhb=1

author: Monkeh
author_rank: Super Contributor
timestamp: March 30, 2014, 01:17:00 am
content: Quote from: don.r on March 30, 2014, 01:15:20 amQuoteRead: Where people use 240V, not 120V.

author: don.r
author_rank: Frequent Contributor
timestamp: March 30, 2014, 01:22:14 am
content: Oh right...You should invest in 120V on your bench. I have 240V on mine and its been a godsend.

author: Monkeh
author_rank: Super Contributor
timestamp: March 30, 2014, 01:23:19 am
content: Quote from: don.r on March 30, 2014, 01:22:14 amSure, let me just get that gigantic transformer so I can power equipment I have to import and pay 20% VAT on, so that I can save.. what, exactly?

author: all_repair
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:55:21 am
content: Quote from: Shock on March 30, 2014, 02:10:11 amCan't agree more. The 240V market are paying too much a premium, not only for the irons but also for the tips, and other spare parts. Why is it so? Guess, market too small for them to protect against the clones? I am leaning to investing on converter and using the 110V versions now. And for 240V version, I bought direct from Aoyue China, and my luck with them have been excellent. The problem with people who get from resellers, traders, on DX, is these people normally try to squeeze the China OEM too much and drag payment too long, and so the OEM normally give them the left over stuff. Quality of clones can vary greatly.

author: EEVblog
author_rank: Unknown
timestamp: March 30, 2014, 04:27:31 am
content: Quote from: Shock on March 30, 2014, 02:10:11 amOf course, I showed it working at the appropriate temp on some high mass parts, and also said it worked fine. It's a given that a temp controlled soldering iron can solder low thermal mass parts, no need to show it soldering SMD or something.

author: calexanian
author_rank: Super Contributor
timestamp: March 30, 2014, 04:33:43 am
content: I am getting the feeling that the reason it was so cheap is that board looks like garbage. A sort of just get these ones out of here type price. Sell them so cheap nobody will complain about the rust and flux and winky LED. The transformer looks surprisingly good, but that may be a bad thing.... Cheap manufacturers who don't use silicon coated laminations will chromate plate the soft iron so it does not rust before varnishing, if it is even varnished. It can lead to leaky, lossy transformers but they look pretty. We fool round eye with pretty. Sell much more. Cost much less..

author: han
author_rank: Frequent Contributor
timestamp: March 30, 2014, 05:08:24 am
content: Cheap as hell..in here for $16 i only can get 40W stick non regulated solder...cheapest regulated one is $160 Aten BrandedHakko 888D is about $200..

author: pickle9000
author_rank: Super Contributor
timestamp: March 30, 2014, 05:37:18 am
content: How much for a typical plastic project box that large? I bet they could make more money just selling the empty box.

author: sleemanj
author_rank: Super Contributor
timestamp: March 30, 2014, 05:49:29 am
content: Quote from: calexanian on March 30, 2014, 04:33:43 amPossibly, but Hobby King have been selling these at this price for quite a long time, and I'm fairly sure they sell out and restock on occasion, so it's obviously something they still get their hands on. I can't imagine there is much money in it, but realistically there's not many components involved either, the biggest cost must be the transformer.The transformer is also the biggest cost in buying this thing due to the shipping, I think to ship that to NZ it would make that $16 USD soldering iron into a $60 USD soldering iron.Which is much less of a deal.I don't know why switch mode supply DC driven irons are not "a thing", I have one (chinese driver, running off a laptop supply, using the typical 900 type handle), it does the job just fine, for a hobbiest, way smaller and lighter, in one my bodged together coreflute enclosures.

author: Kirigozo
author_rank: Contributor
timestamp: March 30, 2014, 05:56:00 am
content: Hobby King don't supply crap!I've never received crap from them. None of the people I know have received crap from then.Only Dave Jones has received a suspect product.Makes you wonder.

author: VK5RC
author_rank: Unknown
timestamp: March 30, 2014, 06:08:33 am
content: I suspect the variance in quality is part of the reason it is so cheap, I wouldn't make it and sell it for that price.115V AC or thereabout is very handy to have around, you often don't have to import a transformer, I didn't need to here in Australia.

author: calexanian
author_rank: Super Contributor
timestamp: March 30, 2014, 06:21:59 am
content: They may just be passing it along at cost to encourage sales of other items as well. It always gets me when you can buy something retail for less that it would cost to ship.

author: hikariuk
author_rank: Unknown
timestamp: March 30, 2014, 07:47:57 am
content: Quote from: calexanian on March 30, 2014, 06:21:59 amLoss leader would make some sense.

author: G7PSK
author_rank: Super Contributor
timestamp: March 30, 2014, 08:54:20 am
content: To sell retail at $16.00 it has to leave the factory gates at $6.00 or under the retailer will mark up 50% the wholesaler will have his cut and there is transport costs as well.It looks to me like they are salvaged water damaged units.

author: firewalker
author_rank: Super Contributor
timestamp: March 30, 2014, 09:02:19 am
content: How do they measure the temperature. Given the price I can't imagine a thermocouple circuit. Just a thermistor away from the heating element? A wire wound resistor with "large" temp coefficient?Alexander.

author: BravoV
author_rank: Super Contributor
timestamp: March 30, 2014, 09:09:45 am
content: Quote from: firewalker on March 30, 2014, 09:02:19 amWho needs stinking temp measuring, as long it melts the solder, QC passed and QC sticker applied !

author: Bored@Work
author_rank: Super Contributor
timestamp: March 30, 2014, 09:28:46 am
content: Quote from: BravoV on March 30, 2014, 09:09:45 amCorrected that for you. You're welcome.

author: BravoV
author_rank: Super Contributor
timestamp: March 30, 2014, 09:32:37 am
content: Quote from: Bored@Work on March 30, 2014, 09:28:46 amThank you Sir, I stand corrected !

author: sleemanj
author_rank: Super Contributor
timestamp: March 30, 2014, 10:05:48 am
content: Quote from: firewalker on March 30, 2014, 09:02:19 amThe heating element includes a thermocouple. These ceramic elements are pretty standard, if you search the forum for A1321 and A1322 you'll find threads about them.

author: Refrigerator
author_rank: Super Contributor
timestamp: March 30, 2014, 12:51:47 pm
content: 15:50 You can see the crusty cap ..... ughhhhh geezus !

author: Unknown
author_rank: Unknown
timestamp: March 30, 2014, 01:18:13 pm
content: Great video!! and a good insight to what you don't get for your money! :-)

author: Rory
author_rank: Frequent Contributor
timestamp: March 30, 2014, 04:31:19 pm
content: A while back, I bought the hot tweezers with a very similar power supply box:First thing that needed to be done was to fix the miswired handpiece, as one side did not heat up to the same temp as the other. The soldering, as you can expect was as abysmal as Dave's $16 beast. It cleaned up pretty nicely, after a bit of documenting which pins on the 8-pin Philmore jack did what. In the end, it does the job.Stating the obvious, on all these ultra-cheap Shenzhen products the most common problem I see is the quality of the soldering during final assembly, combined with poor QC. Is training and equipping assembly workers with usable tools and supplies so prohibitively expensive?

author: Stonent
author_rank: Super Contributor
timestamp: March 30, 2014, 04:50:24 pm
content: Quote from: Kirigozo on March 30, 2014, 05:56:00 amIf you order something cheap, you'll get something cheap. It's not like he ordered something thinking it was going to be good.I think he gave it a fair shake, he said it was better than an unregulated iron.The best price I could find was going to be about $55 total including shipping from Latvia.Hobby king has been out of stock in the US for months apparently.

author: pickle9000
author_rank: Super Contributor
timestamp: March 30, 2014, 05:35:21 pm
content: I would think more than one forum member had one of these way back when. Regardless of the iron good solder is the biggest factor in making a good joint. Sometimes wonder if anyone even remembers what it was like to file an irons tip. I do not long for the "good ol' days".

author: don.r
author_rank: Frequent Contributor
timestamp: March 30, 2014, 06:11:15 pm
content: I wonder if swapping the control board for one of those "Hakko" 936 boards that go for $15 on eBay would help. They appear to be the original 2 chip design but have a 5-pin rather than 7-pin connector so some modding would be needed.http://www.ebay.ca/itm/400569501356?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649They are also good if you have a 24VAC supply so you can roll your own station.

author: Refrigerator
author_rank: Super Contributor
timestamp: March 30, 2014, 06:11:59 pm
content: Quote from: pickle9000 on March 30, 2014, 05:35:21 pmI still use one now, just ordered my first soldering station a few days ago. ( el cheapo one )I might do a teardown of it when i receive it.

author: Unknown
author_rank: Unknown
timestamp: March 30, 2014, 06:29:32 pm
content: Quote from: Shock on March 30, 2014, 03:53:29 pmI totally agree too about it being good value for money; I liked the video because he compared it directly to the real thing which showed what you don't get unless you pay a little bit more.

author: pickle9000
author_rank: Super Contributor
timestamp: March 30, 2014, 06:49:11 pm
content: Quote from: don.r on March 30, 2014, 06:11:15 pmFast recovery is probably the single most perceived feature of a quality iron. To get this has a great deal to do with the construction of the handle (tip mass, temp sensor location and element size and fit). It's worth experimenting with the electronics but will only get you so far.Try larger mass tips and see what happens.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 30, 2014, 06:52:34 pm
content: Quote from: Rory on March 30, 2014, 04:31:19 pmPaying for good tools means the owner of the sweatshop can afford one whore (aka ernai) less.And training? Training is dangerous. A trained employee might ask for more money, for being treated properly, thinking he is actually a valuable human being and all that stuff. Capitalism or communism, both are based on exploiting and suppressing workers to the maximum extend possible.

author: Refrigerator
author_rank: Super Contributor
timestamp: March 30, 2014, 07:29:44 pm
content: Quote from: Bored@Work on March 30, 2014, 06:52:34 pmHitler? I thought you were dead ....

author: SeanB
author_rank: Super Contributor
timestamp: March 30, 2014, 07:37:03 pm
content: Should never have given him that cloning set just because he only had a single nut..............Godwin's law strikes again!

author: Fraser
author_rank: Super Contributor
timestamp: March 30, 2014, 07:39:10 pm
content: I bought a 936 as an emergency back-up but have since pushed it to the back of a cupboard unused. I was a Weller Magnastat user before moving onto PACE temperature controlled irons. I liked them so much that I now have several with different tips fitted. I have a hot air/soldering station that had the same handpiece as the 936. I quickly discarded it as it felt light and cheap in the hand. Performance wasn't too great either.I am no tool snob, but I can honestly state that once you have used a well made and correctly weighted handpiece, the cheap plasticy Chinese handpieces just don't feel 'right'. That is even before switching it on ! If you can possibly afford a decent soldering iron, buy one in preferance to the likes of the cloned 936, you will not regret it in the long run. AND do not forget, you can buy very good named brand soldering irons on the used marketplace. A quality used soldering iron is still a lot better than a new Cheapo unitThere is absolutely nothing to be ashamed of or worried about in buying used equipment that has been cared for.I attach pictures of some of the models of PACE soldering station that I own. They all use the same handpiece design so are great if you like the feel of them. They would all wipe the floor with the Clone 936 and very likely the Hakko irons as well. All cost me less than US$80 each, even the three New Old Stock ones ! (pictures are just grabs from the internet). The newer models are cased in quality cast aluminium enclosures and the ST115 has a vacuum pump included in it for desoldering and 'pick & place' handpieces

author: tszaboo
author_rank: Super Contributor
timestamp: March 30, 2014, 08:44:36 pm
content: Used LM358 <- this is probably the saddest thing in the word if it actually exist.

author: senso
author_rank: Frequent Contributor
timestamp: March 30, 2014, 10:32:25 pm
content: Not if you are into audiophoolery, its already burn-in dude, much better results! lol

author: PA4TIM
author_rank: Super Contributor
timestamp: March 30, 2014, 11:37:14 pm
content: Aurora, I agree. I have a complete Pace MBT250 station besides a Weller WS-81 station. I did not know why I liked the Pace so much but you got me thinking. I think you are right with the balans. It just feels right. I had a few cheap irons and stations befor these. They were very expensive if you devide the price by the time they last ;-)

author: quarros
author_rank: Regular Contributor
timestamp: March 31, 2014, 01:59:38 am
content: Quote from: free_electron on March 29, 2014, 02:13:53 pmOne would think so (Myself included). But the truth is: Zero Ohms from the tip to the mains earth Is correct. Form the ESD safety viewpoint.I know I know it is sound stupid (I ranted about it in another topic). But I tested it with 2 ESD safe soldering station, a Hakko FX888 and a Metcal MX500. Both show zero ohms from tip to mains earth.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 31, 2014, 02:03:44 am
content: A little surprising they didn't use a switching supply to save cost. Maybe they realize that would make it way too suspiciously light...

author: calexanian
author_rank: Super Contributor
timestamp: March 31, 2014, 02:19:00 am
content: We still use weller wtcpt stations at work for the assemblers. We had demo hako and Paige units over the years but they like the weller's more. Their higher temp tips seem to last longer and they use the biggest tips practical for higher thermal capacity. Being all nice new clean boards and components they can really fly. My station and the tech station have mx500's and at home I have one of the old wtcpt's I fixed and nobody wanted to I just brought it home. Works fine for me. If I could only have one station and the metcal was off the table I would go with the wtcpt with the temp control.

author: abdullahseba
author_rank: Frequent Contributor
timestamp: March 31, 2014, 10:05:14 am
content: yi haa swearing free

author: Prizmatic
author_rank: Regular Contributor
timestamp: March 31, 2014, 10:24:48 am
content: Production business?.. Get a durable iron built for the job. Hobbyist?.. Beats a mains iron, works, isn't unsafe. Why the hell not at that price. Heat-up/recovery time? who cares if its better than the one you've got.Makes me chuckle reading some comments, most hobbyists have more pressing things to spend their cash on than an expensive iron.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 31, 2014, 10:47:35 am
content: Quote from: Prizmatic on March 31, 2014, 10:24:48 amHow do you know? How good is that thing protected against overheating? The station, the handpiece or the plastic stand melting / catching fire? No hazardous materials in the handpiece? Proper isolation of the transformer?The thing with a brand product is you can trust them that they thought about all this and have it mostly under control. Occasionally they get it wrong. With a $16 crap product you can be sure they didn't think about any of this and give a flying fart through a rolling doughnut about is. It is a $16 lottery ticket and you are betting the farm on your luck.

author: VK3DRB
author_rank: Super Contributor
timestamp: March 31, 2014, 12:24:14 pm
content: Why can't these comrades invent something decent rather then copying someone else's work, and doing a crap job at it? Violating intellectual property seems like the only thing the communist Chinese are good at. They have has not progressed much further than making and flogging copy watches, as far as ethics and quality goes.Westerners should not be buying this sort of crap on principle. People in poor countries might not be able to afford a good soldering iron, but people in rich countries have no excuse.Besides, quality is remembered long after price is forgotten.The $16 soldering iron is probably illegal. If "Yeehaa!" lied about the ESD Safe, it would make you wonder if it is CE marked honestly. There are plenty of back alley sweatshops in red China illegally marking equipment. In this case it is illegal here in Australia if it does not carry a C-Tick or RCM mark. Our government has lost control of this rubbish entering the country. I think you will find the soldering of the wires onto the transformer tab does not comply with UL-60950 and other safety standards either.DON'T BUY IT.

author: VK3DRB
author_rank: Super Contributor
timestamp: March 31, 2014, 12:34:11 pm
content: Quote from: linux-works on March 29, 2014, 05:48:37 pmI think you will find most test houses (eg:Comtest in Melbourne) will tell you a toothed washer between the chassis and the ring terminal is not allowed for consumer product safety compliance. But a toothed washer between the nut and the ring terminal is OK. Also, nyloc lock nuts are definitely not legal for securing earth connections on mains equipment. Two nuts in a locking configuration are the alternative.

author: Blanketduck
author_rank: Contributor
timestamp: March 31, 2014, 12:40:47 pm
content: Hi everyone, I'm new here (Adam is my name, introductions aside as I need to post this)...This is the YIHUA 937: Newer, more expensive, and more scary. A digital version which retails for $40-$50 here.10mhz 8-bit MCU @ 20 PINS @ 4KB ROM ( big endian - probably an 8051 )SAMSUNG -> Q328E (U3) 20-PINS3F94C4EEZ - DK94K903B1http://www.samsung.com/global/business/semiconductor/product/microcontroller/detail?productId=6803Fairchild Semiconductor 400V Optocoupler/Optoisolator BridgeF -> MOC3041 (U2) 6-PIN317Qhttp://www.fairchildsemi.com/pf/MO/MOC3041M.htmlGeneral purpose dual op amp @ 0.6 V/uS slew @ 1.1Mhz @ 5V supplyLM358N (U4) 8-PINYR1006http://www.st.com/web/en/catalog/sense_power/FM123/SC61/SS1378/PF637214-quadrant AC TRIAC (high voltage switch w/phase control, suggestive that this isn't a PID system)BT137600ENXP -> PJA303 - A5 - 3 PIN( SOLDER MASK SIDE )http://www.nxp.com/documents/data_sheet/BT137-600E.pdfNotice: Don't open the case without gloves. I got flux paste on my gloves. There might be other chemicals.This is useable if you disassemble the handpiece and wash with a damp cloth and quality dishsoap (something like dawn ultra).I highly suggest a commercial neutral PH quat @ 1:40 ratio to disinfect and remove anything on the plastic (I am a BSW also by trade)...The reasoning is that everything has been recycled and nothing is new.The way this was assembled it's suggestive that someone probably could die during the process, and it still would've made it out the door.It was probably too scary to finish so they just put it in the case and sent it out. The soldering iron doesn't fit in the stand,so they crack the top part to make it fit. Normally an adult would have clipped it off, and used a plastic deburring tool. You can get themfor metal too that has rough/rusted or problem edges.Suggestions for improvement to the designers:1.) Drill out the back, deburr the edges, put in an AC receptacle, only use 13 amp rated power cords2.) MOVs + HRC fusing + MPX line caps/filtering3.) Larger caps on the board for more charge on the plates = better thermal mass on the tip3A.) This particular model is designed for explosions, so smaller caps, more space = less chance of PCB burns3B.) Because of A + B = you would have to redesign this as a switching PSU (add quad-wave rectifiers + DC/DC converter + LDO regulators + more things this can't do, etc)4.) Better wiring in the handle, next time use a micrometer to design your tips so it fits snug with the ceramic element ( I suggest designspark mechanical which is free )5.) TRIAC needs a heatsink6.) All those ICs can be replaced by a single SoC7.) Get rid of the 100k potentiometer and replace with a rotary shaft encoder or something else8.) New PCB with more than just one solder mask on the side ( FR2 doesn't cut it )9.) Segment LCD display is a waste of time, graphic LCD instead10.) The samsung MCU isn't because this thing is a PID industrial controller. It's not even remotely fast enough to be one.12.) New case could probably more durable. The plastic standoffs on here crack or break if dropped. Itwould be nice to see some metal threading in the standoffs so you can assemble, and disassemble it as much as you like...I would suggest renaming the station to the YIHUA SOLDERING REVENGE CLASSICS...(similar to creepypasta pokemon conspiracy theories)http://creepypasta.wikia.com/wiki/Lavender_Town_Mysteries:_Missing_Frequencies_and_Lavender_Town_Syndrome_(LTS)Here's the theme song if you want to use this soldering station how it is:

author: Blanketduck
author_rank: Contributor
timestamp: March 31, 2014, 01:50:59 pm
content: This is not a bad utility iron:http://www.wellerred.com/products/40-watt-medium-duty-kit.phpSolomon SR998 power unit to convert it to temp control ( I haven't bought one yet to see if the wiring is good, it's cloned a lot also )...This might be really scary, but worth modifying. You could probably build a good (PID temp controlled) version to sell to people who already have utility irons:http://www.mcmelectronics.com/product/TENMA-21-7927-/21-7927

author: Monkeh
author_rank: Super Contributor
timestamp: March 31, 2014, 03:15:04 pm
content: Quote from: Blanketduck on March 31, 2014, 12:40:47 pmI'm really hoping this is an early april fool's.

author: don.r
author_rank: Frequent Contributor
timestamp: March 31, 2014, 04:08:51 pm
content: Quote from: Blanketduck on March 31, 2014, 01:50:59 pmWithout a temp sensor, you are better off just sticking the iron on a variac or a dimmer controlled socket.

author: T4P
author_rank: Super Contributor
timestamp: April 01, 2014, 04:28:37 am
content: Dave, some background info on the station.It is a 35W unit not a 50W unit or even better, some are 60WI posted a while back on the 936 clones I have and they truly pull 60W each. the yellow and blue one I have (888 in a 936 case ...) acts more like a 888 than a 936.This is what you get for saving 12$Quote from: don.r on March 31, 2014, 04:08:51 pmTrue actually. It is quite literally just a variac in a box. Turning down irons on a variac make them slower than they already areQuote from: VK3DRB on March 31, 2014, 12:24:14 pmThat's why it's cheap. And yes, they actually have a proper shop. What you see here is the cheapest grade of their clones.

author: Blanketduck
author_rank: Contributor
timestamp: April 01, 2014, 07:32:09 am
content: IT'S 12AM: APRIL 1ST in Canada! Happy APRIL FOOLS DAY! Only comes once a year!Here's a video of the YIHUA 937D turned on:The punch line is this ceramic heater. It says "24V 50W TAIWAN" (fake numbers)...It would be very surprising if this could even come close to the new weller utility irons.You don't need any special PSU stuff like I mentioned, because this thing probably can't even beat a 10-25W utility iron...It's just designed for looks, which is why all the safety stuff isn't real, and you'll find too much in one spot, and too little in another...Why would you need the build quality of a 700W-1500W PSU? You wouldn't.My alarm clock and my toothbrush are both much more sophisticated than both of these ( japanese made also )...Also that SOLOMON SR998 is another product to make a quick buck. You won't need it in any way. There's a thermocoupleinside most of those weller utility irons, and they're insulated. They're MUCH safer than these crap chinese things. Trustingone of these crap things to change the volts/amps/frequency/phase on those would probably destroy the iron, or the device itself.They perform really shitty when outside of the spec they were designed for.I doubt you'll see those SR998s, because they're probably eliminated completely.I still want one, but it's because I love making fun of them. I'm sure you could get one if you wanted. A chinese dealerover in eastern canada stocks them on ebay ( weberdisplays )...http://www.ebay.ca/usr/weberdisplaysI think next your review has to be WORLD'S CHEAPEST POWER SUPPLY (look at the YIHUA models there. I have almostevery single thing YIHUA makes except those. They're all hilarious/funny)... I love YIHUA! So entertaining!

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2014, 07:55:55 am
content: Quote from: Blanketduck on March 31, 2014, 12:40:47 pmGreat first post, thanks for contributing.

author: Blanketduck
author_rank: Contributor
timestamp: April 01, 2014, 08:29:41 am
content: Quote from: wilfred on April 01, 2014, 07:46:31 amSorry about lack of embedding. I'll format it properly next time. Ah yes, google and it's search analytics! It looks pretty much like a YIHUA 937D because it's a smouldering, and unrecognizable object. Both band members did solder and build their own instruments (now dead for unrelated reasons)... I would probably be yelling out "I don't get it!" if I had purchased it for $60 and it started on fire.It is nice to see if you want to build a competing low cost station which actually works. Of course I bought for other reasons. One of them is "group" revenge:"The great liability of the engineer compared to men of other professions is that his works are out in the open where all can see them. His acts, step by step, are in hard substance. He cannot bury his mistakes in the grave like the doctors. He cannot argue them into thin air or blame the judge like the lawyers. He cannot, like the architects, cover his failures with trees and vines. He cannot, like the politicians, screen his shortcomings by blaming his opponents and hope that the people will forget. The engineer simply cannot deny that he did it. If his works do not work, he is damned." -Herbert Hoover ( 1874-1964 )http://www.hooverassociation.org/hoover/speeches/engineering_as_a_profession.phpQuote from: EEVblog on April 01, 2014, 07:55:55 amThanks!

author: LEECH666
author_rank: Frequent Contributor
timestamp: April 01, 2014, 07:42:51 pm
content: Quote from: BravoV on March 30, 2014, 09:09:45 amI think this is even more correct ...

author: Christopher
author_rank: Frequent Contributor
timestamp: April 01, 2014, 07:46:11 pm
content: I have the Atten 937b iron, very similar to this for home use. With $3 clone tips off eBay.It is a nice iron for the price, obviously not a JBC (which I use at work), but gets the job done. I have soldered 0402 components as well as 2.5mm^2 wire and it does OK.What do you expect for $20? It serves its purpose for me. If ever I have £200 "spare" for just soldering a few components a month, I'll buy a JBC or Pace iron for at home. In my dreams!!

author: T4P
author_rank: Super Contributor
timestamp: April 01, 2014, 11:55:30 pm
content: Quote from: Blanketduck on April 01, 2014, 07:32:09 amI'm sorry to interrupt your streak but this beats a utility iron hands down. Actually maintains temp roughly (not heating to 480) and not baking itself if you leave it on for too long

author: BravoV
author_rank: Super Contributor
timestamp: April 02, 2014, 12:04:36 am
content: Quote from: NiHaoMike on March 31, 2014, 02:03:44 amWhat stinking switching psu ?All you need is a brick and some cheap glue or screws to stick it in there so it won't wobble ...

author: senso
author_rank: Frequent Contributor
timestamp: April 02, 2014, 01:14:38 am
content: Is that thing real?

author: Luciano2572
author_rank: Contributor
timestamp: April 02, 2014, 01:16:19 am
content: Surprises me that's only 4$ more than my iron;http://i57.tinypic.com/2h2h7b4.jpgIt was 14$, no base/holder ... had to buy one (+10$)And the original tip meltednext step is a hakko for sureedit: removed IMG tags, its too big

author: linux-works
author_rank: Super Contributor
timestamp: April 02, 2014, 01:26:14 am
content: saves weight by using 'virtual transformer technology'.

author: Blanketduck
author_rank: Contributor
timestamp: April 02, 2014, 10:44:42 am
content: Quote from: T4P on April 01, 2014, 11:55:30 pmWhat a troll you are hahah! I love this place! I wouldn't have it any other way.This thing surely bakes itself if you leave it on for too long, especially my version! If not it eventually dies. Murphy's law wins every time!It's not a real hakko, so you can tell the company just wants to sell a working iron, and granted people have bought it and want to use it.I personally think the station is too large and improperly designed. An OSHW board and power unit replacement would be great.The handpiece is somewhat ok. You get what you pay for. 400C can be had @ 10W...It was worth buying, because you can make an OSHW version, and it'll become the new MASS CLONED solder station!It might end up looking like the Weller WSM1 compact soldering station...http://www.newark.com/weller/wsm1/digital-soldering-station-40w/dp/18T1408( here's the weller catalogue page #13 -http://www.apexhandtools.com/weller/pdfs/weller%20catalog.pdf)Idea that I'm too lazy to act on: I'd imagine the best OSHW station would be around 80W. You could make a dual-channel version 160W version, with some kind of terminal block (impedance might be a problem, but it's a soldering iron), so you can replace the socket with one that matches your handpiece of choice: metcal, weller, JBC, pace, etc ...You could avoid legal problems, by just selling the thing as a programmable industrial PID controller with "optional software" and firmware, which the user installs at their own risk...It would be a challenging thing as a lot of irons have specific frequency/power and waveform requirements...(the one line answer so I don't have to say anything about sinusoidal/pulse/square waves and AC/DC conversion)------------------------------------------------------------------------------------------------------------------Here's something unrelated I found enjoyable. This why I love product design forums:"There’s a saying: Arguing with an engineer is a lot like wrestling in the mud with a pig. After a few hours, you realize the pig likes it.Once committed to a logically backed idea that they know to be true, there’s little one can do to change an engineer’s mind, except, of course, provide newly proven evidence to the contrary that the engineer can chew on as fact.But it’s stating their idea and hearing opposing ideas that makes an engineer happier than a pig in mud. And why not? Arguing is an opportunity to open the mind to new ideas, to think, and to reinforce one’s own research and rational.Unfortunately, not everyone sees it that way. For non-engineers, disputes can be more about winning than expanding a discussion."http://www.edn.com/electronics-blogs/serious-fun/4428606/6/Why-engineers-are-better-than-everyone-else

author: Blanketduck
author_rank: Contributor
timestamp: April 02, 2014, 11:29:45 am
content: Yihua should market that all their soldering stations now come with rainbow sponges! Increased sales!I started using rainbow sponges in my soldering stations after watching this thing on youtube:

author: m12lrpv
author_rank: Regular Contributor
timestamp: April 03, 2014, 02:06:24 am
content: Well I polished the turd.Sure the clone was cheap and nasty but the reality is that it's better than what I had which was not temperature controlled. It was also cheaper than what I could justify spending money on and it workes. It was no big deal to replace many of the components with stuff I had in my parts drawer.Plus I needed something with a smaller tip than what I had because I was having issues soldering the 0805 and 0603 caps and resistors with my old iron so its a win for me.

author: pickle9000
author_rank: Super Contributor
timestamp: April 03, 2014, 03:08:46 am
content: @m12lrpvNicely polished, probably be worth changing the pot for that extra shine.But seriously you where probably soldering with a sub-standard iron. The skill of the person soldering and the solder is critical to doing a good job and this is a good indication of that. Nice job.

author: m12lrpv
author_rank: Regular Contributor
timestamp: April 03, 2014, 03:21:55 am
content: Quote from: pickle9000 on April 03, 2014, 03:08:46 amthanks.I didn't have a 50k pot that was suitable otherwise that would have gone tooI might order one when I order the name brand replacement for the Triac and the illuminated power switch.I agree with the solder quality being an issue. I ended up wicking off most of the solder that was on there and replacing it with my multi core solder. The stuff that was on there would melt but wouldn't flow.

author: linux-works
author_rank: Super Contributor
timestamp: April 03, 2014, 03:30:20 am
content: you probably didn't have to remove the solder; just add real flux, let it flow and then clean the board.

author: saturation
author_rank: Super Contributor
timestamp: April 05, 2014, 02:36:19 pm
content: This is a good video to show what clones or lesser soldering stations do not give you compared to the better brands, and where the extra cost goes into. We've had many forum topics on it, but no video shows the deficiencies in action particularly side by side comparison, IPC quality vs iffy stations.

author: m12lrpv
author_rank: Regular Contributor
timestamp: April 08, 2014, 09:16:50 am
content: I've just replaced the triac in mine with a NXP BT137 600D and now there is no transformer hum at all. I initially though I'd broken it when it went quiet but now it actually seems to work better.Problem now is I can't use the previously audible hum to tell me that I've left it on.

author: miguelvp
author_rank: Super Contributor
timestamp: April 10, 2014, 04:46:22 am
content: So, because of my current budget (because of buying dev boards like crazy) and my older soldering iron being more crap than this, I got a clone but it's made by Tenma. It was 30 some dollars. I haven't opened it up yet (I know I should and I will).One thing I'm doing is to get the hakko 908-CK conversion kit to make it a large Iron and got an extra 5 original hakko 908 chisel tips (for a total of 6).It will take a bit longer to heat up, and the Tenma seems to heat up pretty quick, but I wanted to add the extra iron mass, so that at least it's decent. It seems like the conversion kit will fit fine but I'll have to wait until it arrives (not many available out there).

author: Bored@Work
author_rank: Super Contributor
timestamp: April 10, 2014, 05:02:17 am
content: Quote from: miguelvp on April 10, 2014, 04:46:22 amTenma is a Farnell/Element14/CPC/Newark/MCM/<insert company name of the day> brand. They don't build that stuff, they slap the name onto stuff build by others, to disguise the true origin.

author: Jason114
author_rank: Newbie
timestamp: April 11, 2014, 01:30:43 am
content: Quote from: Christopher on April 01, 2014, 07:46:11 pmI have a Atten soldering station as well. It is low priced and with good quality. For cheap soldering stations, you can choose Yihua, Atten, Aoyue.

author: miguelvp
author_rank: Super Contributor
timestamp: April 14, 2014, 08:21:22 pm
content: So I got the hakko 908-CK conversion kit and it fits my clone, it came with:1 - 900L-T-3.2D Large Mass Tip1 - B1787 Enclosure1 - B1794 Enclosure Nut1 - B2033 NippleChanging the iron from a 907 medium iron to a 908 large iron. I also got an extra 5 900L-T-3.2D tips from tequipment.net. I would have bought the conversion kit from them but they don't have it anymore.Here is the 908-CK fitted and below the 907 clone.

author: AndersAnd
author_rank: Frequent Contributor
timestamp: May 08, 2014, 08:59:30 pm
content: Quote from: EEVblog on March 29, 2014, 01:18:27 pmI believe there's an error in this schematic. Anode and cathode of ZD2 (5.1V zener diode) looks to be swapped in this schematic. If mounted this way the zener diode will be forward biased an only work as a regular diode instead of a reverse biased 5.1V zener diode.

author: amyk
author_rank: Super Contributor
timestamp: May 10, 2014, 11:56:24 am
content: The different behaviour of the LED is due to the fact that the heater is driven with PWM, and so is the LED - as it approaches the setpoint the duty cycle reduces, so it looks like it's gradually dimming before it turns off.Here's an Aoyue 936 schematic, which is a somewhat more complex controller for thermocouple elements (includes a TL431 and anoptocoupler- don't know why the latter would be needed, since the iron is already isolated through the transformer):http://s020.radikal.ru/i706/1304/f7/f05b997dbf33.jpgAnother 936 clone controller, with TL431 but no optocoupler:http://images.people.overclockers.ru/205524.jpgQuote from: AndersAnd on May 08, 2014, 08:59:30 pmAfter looking at the schematic and this:http://cdn.head-fi.org/c/cd/cdd2b519_PCB_Compare.pngI think you're right.

author: han
author_rank: Frequent Contributor
timestamp: May 10, 2014, 12:26:18 pm
content: buying one

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: June 19, 2015, 08:23:54 am
content: Hi Folks..I purchased a Hobby King Yihua 936, obviously there are faults that most are fixed, but, looking at the transformer, there is no way it's more than 35~40VA.My question, I am using this as a 2nd station and building a complete DIY 936 clone OEM PCB circuit and non OEM parts etc. I need suitable transformers, for these units. I read the 936 is ~ 60VA transformer, I can find a 50VA to fit the transformer mount posts (of the case) but suggest a 73~75VA unit (or even a 100VA) would be more suited.Has anyone built or modified such a unit and what transformer did you use? So far I have searched RS/Element14/fleabay/Jaycar/Altronics (Australian user) and found some but they won't fit the case mounts. I wanted these units for easy stacking, I need dual irons and there are plenty of cheap parts available (yes I know non original). I am retiring my home made dual iron Adcola/Royel Hybrid system I built back in the 80's as it is just too low in wattage. Yes I have other higher wattage irons (non temp control) but wanted a controllable station on the cheap with dual irons.I'm a cheap arsed but know the need to pay for a decent iron/tips/controller PCB and transformer so any advice welcomed (even considering buying a proper Hakko 907M iron, full price, but where?).

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: June 23, 2015, 08:08:58 am
content: Ok purchased an original C1143 iron, Hakko 907, from RS components, plus some OEM tips, but noted the iron or packing does not state "ESD safe". Looking at the iron, its definitely Hakko but was wondering...is this iron indeed for their 936ESD stations or is it one of their older white version versions? The iron is white!Also I'm assuming the Hakko 936 station is a 50VA transformer?Anyone!

author: bosondehiggs
author_rank: Newbie
timestamp: July 02, 2015, 02:54:32 am
content: Hello my yihua 936 burn today (connector shortcut)Can someone tell me value for R1,R2 and fuse?Thanks

author: bosondehiggs
author_rank: Newbie
timestamp: July 02, 2015, 04:22:34 am
content: thank you!any idea for fuse?

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 02, 2015, 11:08:49 pm
content: Ok checked mine be careful there are probably many variants of this PCB out there. Mine is marked YH 936AV10-3IQR1 is 330 ohm; R2 is 150 ohm; fuse is 1Amp.I'm changing my PCB/Transformer to OEM copy (and 75VA transformer) as the std ver is ok heating a pencil tip but struggles badly with a 3.2 chisel tip. Also I have an OEM 907 iron and 907 clone (with same heater/PTC heater feedback) so commonality of changing irons is important to me. The Yihua iron uses a thermocouple feedback and is probably around 35~40W iron heat max (at best)!I'd suggest if your resistors went then you have another issue that caused this.....looking for a cct to help in this atm for you.edit:ok looking at PCB...looks as if they come from 24V in/triac and looks as if your triac is probably bad, also check D1!

author: bosondehiggs
author_rank: Newbie
timestamp: July 03, 2015, 12:25:29 am
content: thank you .I have same pcb, i need to buy fuse for test.I check D1 look good.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 05, 2015, 07:02:14 am
content: Forgot to say, fuse is 1A for 240V, 2A for 110V!Don't know which version power input you have so check this,

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 12, 2015, 01:39:57 am
content: Finally....Ok made some Hakko OEM copy PCBs and ordered a front panel and new case from fleabay as well as a host of parts, including new transformers. I now have a 936 station OEM copy ( although I'm using a 75VA 24V 2ndry transformer) and an original 907 iron (from RS) including a handful of OEM Hakko tips. Also changed the main power switch to a neon type and put in proper M205 cartridge fuses on this main switch, with a new sub PCB for this. Also put M205 cartridge fuse on the main PCB for 24V (transformer secondary) pwr to PCB. Cannot think for the life of me why Hakko didn't originally do this.Also doing the "on power LED mod". Forgive my photographic skills!This new system heats much much faster than the Yihua (25~30 secs or less with 3.2mm chisel tip) and has no problems doing big tasks and has much better thermal stability. Pretty much because the Yihua transformer was ~35VA! The Yihua heater tip is a nichrome wire in a ceramic tube and the ceramic end cracked on mine and is showing nichrome heater wire...barely ~1mm away from the tip metal (ground). Not good.Also I found the Yihua uses a non std thermocouple temp feedback (mentioned before by others) which is not the same as the Hakko 907 iron PTC feedback. Funny enough I found a place in Aust selling very good copies of the 907 iron with the same ceramic heater and PTC feedback as the Hakko for ~$20, not bad indeed! Now I can change irons and keep calibration, I've ordered a thermocouple tip temp calibrator),Just doing the 2nd station now but using a 50VA transformer for the 2nd one.One for the safety inspectors..... my Yihua soldering station they wired the active/neutral wrong and switch/fused the wrong line. The Active (Line) was the blue wire, the Neutral (N) was the brown wire (it should be the other way round the moulded plug is made/wired wrong). The main switch also switched and fused this brown (Neutral) wire. At least the earth was correct! Safety standards......Ahhh yes China has a long way to go!

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2015, 11:21:28 am
content: Quote from: wasyoungonce on July 12, 2015, 01:39:57 amElectric current goes down both those wires with equal intensity.(And large areas of the world have plugs that can be inserted either way around...)

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 13, 2015, 12:18:08 am
content: Quote from: Fungus on July 12, 2015, 11:21:28 amQuite cognisant with what electrical current flows in must flow out. The Australian 230V type power plug, is unique to a small number of countries, Australia, New Zealand, Argentina, ...China is similar in some areas. This plug cannot be "inserted the other way round". They all use the same colour codes (that I know of) and switch (or should switch) active or line "brown".http://www.openelectrical.org/wiki/index.php?title=Cable_Colour_CodeOf course, with 900+ posts, you would be very aware that not switching active allows electrical charge to be present thru the transformer primary and to the switch at all times, even when the station is switched off (but still plugged in to an "on"power point). One can forgive some small electrical faux pas from China ....like lack of star washers on transformer ground but to mould the plug wrong colour code is an electrical cardinal sin for obvious reasons.Just trying to put this out so others are aware of this hazard.

author: Monkeh
author_rank: Super Contributor
timestamp: July 13, 2015, 01:12:53 am
content: Would you care to elaborate on where, exactly, the hazard of incorrect polarity infunctional switchingfor a double-insulated device arises?

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 13, 2015, 03:19:24 am
content: Quote from: Monkeh on July 13, 2015, 01:12:53 amYep, an over-voltage or lightening strike on power line (happens a lot in some tropical areas), primary of transformer is still live (because it hasn't been switched off), shorts to earth (arc over)...the rest is obvious. Yes, this should activate house RCDs (if fitted, RCDs are fitted by Australian standards in homes since ~ yr 1998'ish), yes its double insulated but the hazard is with the primary not being switched off.Its really poor practice not to switch the active, in fact dangerous. Especially if someone is poking around inside the unit thinking it's switched off. Oh I should also say that this device is not really a double insulated device by definition.https://en.wikipedia.org/wiki/Appliance_classesI changed my switch to an SS21 double pole single throw (neon) as someone else did in this thread. But that was for visual purposes.edit:ahh looks as if the Argentine electrical plug is wired opposite to the Australian ..quote wiki ..."The most important difference from the Australian plug is that the Argentinean plug is wired with the line and neutral contacts reversed."https://en.wikipedia.org/wiki/AC_power_plugs_and_socketsNow there's your problem...Argentine/Australia...all very similar spelling!

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2015, 10:28:29 am
content: Quote from: wasyoungonce on July 13, 2015, 12:18:08 amSo... all those other countries are living in constant mortal danger. Got it!

author: HighVoltage
author_rank: Super Contributor
timestamp: July 13, 2015, 10:44:23 am
content: Germany has pretty safe plugs but they can be inserted either way around and we do not have a problem because of this.

author: Monkeh
author_rank: Super Contributor
timestamp: July 13, 2015, 11:11:03 am
content: Quote from: wasyoungonce on July 13, 2015, 03:19:24 amSorry, but again, this is functional switching, not isolation, and in many cases polarity is not ensured. It is nowhere near as big a deal as you make it out to be.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 13, 2015, 11:39:32 pm
content: It's only a problem in that as stated if someone opens the unit and is working on it expecting the Active to be off...! But in respect to switching active, 230V is a lot more electrical shock dangerous than 110V. Body resistance decreases with increasing voltage and increasing voltage increases current flow thru the body...maybe because, this is why the active must be switch in Australia.I really cannot comment on other world systems and their regs. But for Australia, this product would be banned if known...this is why I raised this.

author: Monkeh
author_rank: Super Contributor
timestamp: July 14, 2015, 12:16:45 am
content: Quote from: wasyoungonce on July 13, 2015, 11:39:32 pmDo I need to elaborate on functional switching vs isolation?QuoteThe active must be switched in Australia (and the UK) only because we have theluxuryof the reasonableassumptionof specific polarity.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 14, 2015, 07:34:00 am
content: Quote from: Monkeh on July 14, 2015, 12:16:45 amWell is the item intrinsically safe? No because potential is present in the primary of the transformer at all times unless off at the power point.When the assumption of specific polarity switching is found to be wrong, then pretty much IMHO it's worth mentioning. Well I thought so. So we have to disagree on these but understand each other perspective.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2015, 10:45:30 am
content: Quote from: wasyoungonce on July 14, 2015, 07:34:00 amThat's true but it seems like a very minor safety problem to me.You could also point out that the wire inside the power cable is still live(Unless you're British, in which case there's a fuse inside the plug to disconnect it! Why don't you move over there, just in case?)

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 14, 2015, 11:39:39 am
content: Quote from: Fungus on July 14, 2015, 10:45:30 amHa move to England....my Ancestors were sent out here from England...I don't think they want us back!Yes the Blue wire is wired to the active, not switched, and yes this is fused (as mentioned) prior to the transformer...is this where your heading? Aka any short the fuse blows? I do concur.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2015, 12:20:19 pm
content: Quote from: wasyoungonce on July 14, 2015, 11:39:39 amI'm not sure where I'm headed exactly.I'm trying to think of a situation where "live transformer primary" is dangerous but where many lives would be saved if it was done 'correctly'.If you've taken the cover off without unplugging it first and are poking random wires with a screwdriver then ... you could also be doing it with an intact fuse when some other component has failed and the iron isn't getting hot. Maybe you need to learn that lesson the hard way.

author: McBryce
author_rank: Super Contributor
timestamp: July 14, 2015, 01:45:23 pm
content: In many countries even if it was done "correctly" the plug can still be pushed into the wall socket in both directions (making it "incorrect" again), which is why you learn that you shouldn't "poke around with a screwdriver" if the device is still plugged in.McBryce.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: July 14, 2015, 11:12:37 pm
content: Sorry folks...I had an old timer moment...power active is live at the transformer before the fuse and switch, I wrote it wrong above.My first thought was this item is intrinsically safe because it uses a plastic box and you really cannot touch any live part, but it's not because of the wiring. Yes it's rare to see transformers short, but I have seen it and bejesus they stink when they go up! But as you said it's very rare because of the way they are made etc. But there again, if they mfgr cannot wire the switch and plug right is the transformer any better. Well their grounding wasn't.Which bring me to my finalisation, yes this is not right, yes it presents little danger but it does present some hazards. Yes it would fail Australian safety standards but is effectively safe enough for users. But I guess I am not one of the "most" users...I pull things apart (and sometimes cannot get them back together!) to check, correct and improve.In my case, with this soldering station, I tossed all of the insides because it was under performing and make my own, changing the switch and lead of courseCertainly I wasn't particularly aware that OS plugs could be plugged in either way (well not quite I did have some idiot twist the pins of a 110V plug to fit an Australian socket for a light table, plugged it in and bang!), hadn't really thought about it much lately (which I admit is naive) even though I've worked with a lot of French/US Avionic gear, mostly powered by 115V 3phase. But yes US 110V plugs would be a nightmare also aware they have 220V in some households (for higher powered domestic appliances)....going to look those plugs up now!

author: Mati256
author_rank: Contributor
timestamp: January 04, 2017, 04:27:07 pm
content: Hello. I see there are 110V and 220V versions of this cheap station. Looks like 220V ships from Hong Kong adding time and money to the item. Would I be ok purchasing a 110V and changing the transformer for a 220V 50Hz or the electronics require it to be 60Hz? Would it be better to use a Power Converter (although the ones I can get here don't have a ground connection!)?What's the secondary for this transformer? 24V?Thanks!

author: mariush
author_rank: Super Contributor
timestamp: January 04, 2017, 05:58:06 pm
content: I don't think the frequency's a problem.There's a 24v or 26v AC winding (i've seen 28v AC in pictures for some stations ) for the heater element but there's also at least one other secondary winding for 10v AC or something like that, which is meant to power the electronics inside (3.3v or 5v for microcontroller using a linear regulator) and up to 15v for opamp or comparator or whatever it uses to measure temperature and compare with configured temperature limit.I suppose you could buy a transformer with just one secondary winding and hide inside the case a separate power supply, let's say a small wall adapter to give 12v DC or something like that.You'd have to open your soldering station and check the circuit to see what it does with the windings coming from the transformer.

author: Mati256
author_rank: Contributor
timestamp: January 04, 2017, 09:00:03 pm
content: Thanks for the answer. More than one secondary? That's new. They have only one secondary in the pictures I have seen.I could always buy the 110V version, meassure all the secondary coils and buy a custome transformer, but that might end up costing more than shipping it from Hong Kong.

author: mariush
author_rank: Super Contributor
timestamp: January 04, 2017, 09:19:49 pm
content: Quote from: Mati256 on January 04, 2017, 09:00:03 pmYou can see for yourself on page 4 of this thread, where dude shows the insides of Yihua 937 he bought :https://www.eevblog.com/forum/blog/eevblog-596-world's-cheapest-soldering-station-yihua-936/msg416686/#msg416686You can see the picture of the transformer, a 24v winding and a 10v winding.The 10v winding is probably less than 100mA, there's a diode for half wave rectification and a capacitors to smooth out the dc voltage and then a 7805 regulator or something like that takes 7...15v down to 5v ... just for the microcontroller and the lm358 opamp and the 3 led digits (multiplexed)

author: Mati256
author_rank: Contributor
timestamp: January 04, 2017, 09:42:10 pm
content: Ah, I see. But I'm talking about the 936 here, its analogue. The 937 is digital so it's a different circuit.

author: mariush
author_rank: Super Contributor
timestamp: January 05, 2017, 12:40:28 am
content: Quote from: Mati256 on January 04, 2017, 09:42:10 pmThe analogue 936 would still need to power the opamp or comparator with some voltage ... which won't be 24v AC.Here's the original Hakko 936 schematic...http://dalincom.ru/datasheet/HAKKO_936_schematic.pdfAs you can see, it uses a quad opamp LM324 and it's powered with ~ -5v and +5v , you can see there it uses two 5.1v zener diodes to create the positive and negative rails for the opamp.Some third party designs / clones simply use a separate winding keeping the high voltage winding separate, just for the heater. Or they use better opamps or don't care about opams not being able to get output close to 0v, so they use only ground and positive voltage instead of feeding opamps with negative and positive voltages.

author: nickeevblog10
author_rank: Contributor
timestamp: May 03, 2019, 01:38:46 am
content: I have an Atten 936 manufactured by Shenzhen Atten Electronics which stopped working and so far have tested and ready to replace the BT137 600 with a NXP BT137 600E.After reading through the posts in this thread decided someone might like to see some photos of my version of this solder station and ask two questions and I will put a heat sink under the replacement Mosfet.In one photo I have marked a vertical rectangle and a circle both in Yellow. I guess the vertical rectangle is showing off.The circle is around the area where the Ground was soldered but without first checking precisely where the Ground was soldered I removed it and forgot what I had looked at. All I could remember was it seemed to be soldered to both tracks where you see the ground soldered now. Is this correct and to which track or tracks should the Ground Wire be soldered?EDITED: In the second photo the Ground Wire in the circle is supposed to connect to either both or to one of the tracks on the board. It is so long ago I removed the wire I forgot how it was connected but remember is seemed to be connected to both tracks. The half of the wire I soldered to the longer left track may not be useful at all because that track comes from the middle solder iron pin, the middle of seven pins, and that track is about 15 mm long connects to no other components on either side of the board. The shorter wire does connect to other components and so connects to other tracks on the board.So should that Green Ground(Earth I suppose) wire need only be connected(soldered) to the track which has components connected to the circuit on the board?

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 12:09:24 am
content: How should the zener diode ZD2 be in the schematic of the hakko 936. What would be the correct position?

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 12:14:54 am
content: Hello EEVblog I like your YouTube videos I always look at them although I do not handle English well. Well I would like to know if this circuit of the hakko 936 is going well? I would like to make this station. I read in a comment that the zenner diode ZD2 is wrong or badly placed I would like to know how I would have to mount it. I hope you can help me. Greetings thank you.

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 12:34:05 am
content: Quote from: EEVblog on March 29, 2014, 01:18:27 pmHello EEVblog I like your YouTube videos I always look at them although I do not handle English well. Well I would like to know if this circuit of the hakko 936 is going well? I would like to make this station. I read in a comment that the zenner diode ZD2 is wrong or badly placed I would like to know how I would have to mount it. I hope you can help me. Greetings thank you.

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 12:36:29 am
content: Quote from: AndersAnd on May 08, 2014, 08:59:30 pmHow should the zener diode ZD2 be in the schematic of the hakko 936. What would be the correct position?

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 12:37:24 am
content: Quote from: amyk on May 10, 2014, 11:56:24 amHow should the zener diode ZD2 be in the schematic of the hakko 936. What would be the correct position?

author: nickeevblog10
author_rank: Contributor
timestamp: May 08, 2019, 03:31:21 am
content: LucasArg...These two links are not working.There is many different board layouts for the imitation 936 boards.Mine is manufactured by Shenzhen in China and appears different to others.http://images.people.overclockers.ru/205524.jpghttp://cdn.head-fi.org/c/cd/cdd2b519_PCB_Compare.png

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 04:37:57 am
content: Quote from: nickeevblog10 on May 08, 2019, 03:31:21 amHello friend, if these links that you published do not work in other previous topics I think I have tried to see them. The cricuitos that I am seeing to make me a station is from hakko 936.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: May 08, 2019, 05:39:47 am
content: Hi Lucas I sent you link to my files on google drive. I think ZD1 is incorrect on most "Web" images. I sent you eagle PCB files and pdf on correct layout.This is an old design, works ok, maybe there are newer better designs out there. That said I like the "analogue knob". Buying a pre-made PCB or kit from fleabay would be cheaper. But most 936 PCBs are poor copies missing many parts.

author: LucasArg
author_rank: Newbie
timestamp: May 08, 2019, 05:57:20 am
content: Quote from: wasyoungonce on May 08, 2019, 05:39:47 amThank you very much friend. Now I hope to have my station thanks to you because in Argentina they are somewhat expensive for me and bringing from outside is complicated. Any question I will be communicating with you.

author: nickeevblog10
author_rank: Contributor
timestamp: May 08, 2019, 06:44:19 am
content: What do you think is the problem when I press the heatsink on the Mosfet the LED goes off and will only come on when I turn the knob higher then lower back and forth.I am not so interested in this not.I might buy a board and a 5 pin soldering iron for this Shenzhen Atten 936b, I can not find a 7 pin replacement board for a seven pin solder iron.Thank you.

author: nickeevblog10
author_rank: Contributor
timestamp: May 08, 2019, 07:07:14 am
content: I found on the schematic 26 MAR 2011 v1.7 PC BOARD AS VIEWED FROM THE COMPONENT SIDE ZD2 position seen to left of PVR temp Control is from top to bottom Z D 2. So writing on schematic for ZD2 is top to bottom on schematic picture.

author: Feliciano
author_rank: Frequent Contributor
timestamp: June 08, 2019, 04:51:29 pm
content: FWIW: Another version of the 1IC controller board (not as nasty as the Dave's). Careful with the potentiometer, for the reviews I read it's very flimsy.

author: Feliciano
author_rank: Frequent Contributor
timestamp: July 07, 2019, 02:45:22 pm
content: BTW, previously in this thread it was mentioned:Quote from: Tuppe on March 29, 2014, 04:29:42 pmBut I'm curious about the other models: does anyone knows the alleged difference between: those and 936a+, 936b, 936e? (Some 936d/937d has a digital display, some 936d has an USB port).