Precision Gold Soldering Station N16CH Maplin (ZD-937-A)(LU3204-00) - Page 1
Forum section: electronics / general

author: binbags
author_rank: Newbie
timestamp: May 23, 2012, 08:49:23 am
content: Hi AllI have just joined the forum as I was searching for help on my Maplin N16CH soldering station and was reading the review by member "ciccio" very informative and the pdf document submitted by "Free Thinker" very useful, an excellent article by all.As mentioned above, I have the Maplin version and is by what I can see, not in the same quality as the LU3204-00. The final LCD driver IC is just a blob on the PCB and covered in resin.Down to my problem with my N16CH. From switch on the unit functions OK, the LCD display shows all OK for about 3-5 seconds then goes into partial display mode (only certain segments are displayed). If you switch off and on again then the same happens but showing other segments of the LCD display.I have taken a couple of photos to show my PCB and display readout.I have tried replaced all the capacitors that are used in the station, but to no success.Do you think that you can help me with this problem?Alan

author: david77
author_rank: Frequent Contributor
timestamp: May 23, 2012, 09:54:15 am
content: I don't want to appear rude, but have you created that soldering mess in the last picture?Can't be sure from the low-res picture but I'd say there are a lot of cold joints, they could cause all kinds of errors.The first thing I would do is clean up that board. Resolder all the joints, clean off the flux residue and try again.Worst case could be the blob is broken - then this thing is ready for the bin.

author: binbags
author_rank: Newbie
timestamp: May 23, 2012, 02:23:52 pm
content: Hi David77This is how I purchased it from Maplin, it was'nt intil the other day that I came to use it and found it faulty.I agree the workmanship is awful for what it cost £49. I think this is a very poor copy of the ZD-937.There are some pics for you to look at.Alan

author: david77
author_rank: Frequent Contributor
timestamp: May 23, 2012, 03:26:29 pm
content: Bloody hell. If that's the way you got that iron you may have a chance it'll work after resoldering everything. I'm not sure if it's worth the effort, though.The more I hear about Maplin the more I'm shocked.

author: binbags
author_rank: Newbie
timestamp: May 23, 2012, 03:34:29 pm
content: Hi DavidYes, me too. Once bit twice shy.I have started to de-solder the board, the funny thing is that the iron works, it's just the display that is up the wall. As you said lets hope it's just a dry joint. They have used the new silver loaded solder on this board, I hate the stuff, there is no proper flow with this.I will keep you posted, Thursday seems like a lucky day for Soldering Stations.Alan

author: poorchava
author_rank: Super Contributor
timestamp: May 23, 2012, 03:44:20 pm
content: Omg, it look as if they were soldering this with 70's era transformer soldering gun. Whatever kind of solder alloy this is, I'd call these pictures a prime example how solder joints should NOT look like. Also the design itself contains some epic fails (like the placement of capacitors). Flux all over the place. Amount of solder is about 2-3 times of what would really be needed.As for the reason of failure I'd say they could've damaged some part by overheating the board. If you feel lucky, you can try to desolder and then properly solder the components that are soldered badly (that would be almost all of them). I may be fault of cold joint or cracked terminals of some smd device.

author: T4P
author_rank: Super Contributor
timestamp: May 23, 2012, 03:58:58 pm
content: Quote from: poorchava on May 23, 2012, 03:44:20 pmLet's put this into the National EEVBlog Museum of Electronics in the Shame corner as a warning from history and as a prime example(use the product number as a joke everywhere) of a terrible soldering job such as this :

author: binbags
author_rank: Newbie
timestamp: May 23, 2012, 06:18:23 pm
content: Hi AllThanks for your replies, as I said I am in the process of de-soldering all the major components on the board. I have already found one piece of track that has lifted, so maybe this is the problem, keep my fingers crossed and carry on doing what I can with the rest. I should have it done by tomorrow night.Not sure if this follows the circuit that was supplied by “Free Thinker” and the blob chip is the HT1621B LCD driver chip. I could make an auxiliary pcb to carry the HT1621B then use flying leads to connect it to the main board and LCD. I then think that this is a lot of extra work and time, do I want all these problems, although I hate things beating me.Alan

author: poorchava
author_rank: Super Contributor
timestamp: May 23, 2012, 09:29:57 pm
content: If you ditch this crap and choose to buy another soldering station, I recommend Xytronic. It's a Taiwanese company, but here in Poland they are considered as a solid piece of equipment for hobby/serious hobby use (which is probably because stuff like Hakko, Weller and Pace are our of range for hobbyists).I never saw what would really look like a fake one (too cheap to counterfeit?). Many different types of irons, hot tweezers, hot airs and even infra red rework systems (although these are not cheap). I recently bought LF1600 with standard 108ESD pencil (80W, grounded, ceramic heater, digital temp control) and I'm really pleased with it. I bought it for PLN 355 which is roughly $110.It's real joy to use this tool as compared to Pensol Solomon SL20CMC (chinese, not that cheap, extremly durable - they were used in my university's student workshops and survived)which i was using before.

author: Afrotechmods
author_rank: Unknown
timestamp: May 23, 2012, 11:25:36 pm
content: I really, really don't think you should be trying to repair that thing. That's the worst piece of shit build quality I have ever seen and even if you replace most of the components and get it working again there's a good chance another failure will pop up somewhere and start a fire or shock you. Think about it for a second - you are plugging this thing into 240VAC, does it look trustworthy to you?

author: mAJORD
author_rank: Contributor
timestamp: May 24, 2012, 12:29:33 pm
content: Quote from: poorchava on May 23, 2012, 03:44:20 pmalways love seeing a tracks going under screw heads also

author: binbags
author_rank: Newbie
timestamp: May 24, 2012, 12:44:09 pm
content: Hi AllI have done as much as I can in stripping, cleaning and re-building the PCB.It is just the same as before; the display comes on all OK, 5 seconds later the display is only showing partial characters although the iron is working as normal. So it has to be the LCD driver chip at fault. I have checked the supply to all the IC's (5.01vdc).I am going to give it up as a bad job;maybe I will use the case for another temperature controlled iron circuit when I find one, or a doorstop.As you have all said this piece of kit beggar’s belief in its workmanship. Must have been made on a Monday morning, by someone who could not see properly.

author: poorchava
author_rank: Super Contributor
timestamp: May 28, 2012, 04:20:57 pm
content: As I say, If it's for hobby - then go for Xytronic. I believe that they began cloning Hakko stuff or at least copied some of their solutions, but apparently at some point they went on and started making apparently original designs. Never saw an obvious fake around. Build quality is very good (no idea how about inside, but I don't wanna void my warranty)

author: T4P
author_rank: Super Contributor
timestamp: May 28, 2012, 04:22:54 pm
content: Quote from: poorchava on May 28, 2012, 04:20:57 pmit's pretty pricey around here ... 178$ for a simple station ... WUT

author: poorchava
author_rank: Super Contributor
timestamp: May 29, 2012, 07:50:18 am
content: Are you talking about LF1600? I bought it for what would be about $110. Weird... maybe your customs office has some insane rates on that stuff? I wouldn't be willing to pay $180 for that either (and for no other station for that matter - it's for hobby use)

author: T4P
author_rank: Super Contributor
timestamp: May 29, 2012, 08:02:50 am
content: Quote from: poorchava on May 29, 2012, 07:50:18 amSGD. so take USD multiply by 1.3/1.6 but it is pointless to pay 178$ a 68$ station can do even if it's a cloneI'd pay that for a FX-888 which costs 200$ or a 95USD$ FX-951 Clone ( yes, there are ... )

author: binbags
author_rank: Newbie
timestamp: June 01, 2012, 12:32:19 pm
content: Hi AllAs a last stand I have contacted Ningbo Zhongdi in China. To be fair they were very fast and communicative with me. What I had asked them was could they supply a new PCB for Maplin N16CH iron. They replied this morning, saying that the cost of the board and postage was prohibitive and that I should go a buy a second unit from Maplin, not a chance. So it is assigned to the re-cycle bin.The pre-programmed AT89c2051 is still OK as are most of the other chips, apart from the LCD driver one which has caused all the problems. I have ordered some HT1621B driver chips from China just to play around with.It would be nice the try and find the data sheet on the special LCD as this is also good, so if anyone has this data would they like to share it? Or can anyone identify the pin numbers for me?

author: Sparky49
author_rank: Regular Contributor
timestamp: June 12, 2012, 05:00:33 pm
content: Glad to hear you sorted it out. I would never recommend getting stuff from Maplins - everything about them is rubbish.They only carry something like 5 of each components, poor equipment like this, and they sell out of date books like money grabbing rats.

author: T4P
author_rank: Super Contributor
timestamp: June 12, 2012, 06:15:08 pm
content: Quote from: Sparky49 on June 12, 2012, 05:00:33 pmThey aren't called Craplins for a reason

author: binbags
author_rank: Newbie
timestamp: July 10, 2012, 08:26:30 am
content: Hi AllJust to add a short note to final stages of my N16CH (ZD937) soldering station. I contacted Ningbo Zhongdi in China. They were more than very helpful, they have sent to me a complete PCB with display, all at there expense including courier dispatch to me; this was all done by about 6 days. So it’s a thumb up for them from me.The new PCB is of the new style, with the HT1621B as a 48SSOP chip in its own right, not a blob on the board like the old board, sees attachments. I have also attached a drawing of the LCD pin out.As a last thought on the old board, I think that this had nothing to do with Ningbo Zhongdi as the workmanship is far superior, there are still some after-thoughts as far as component placement is concerned, but with the LCD being so close to the board, that is understandable.

author: Simon
author_rank: Unknown
timestamp: July 10, 2012, 10:21:19 am
content: Haven't read the whole thread but yes, avoid naplins at all costs. Maplin makes eBay look like Jesus Chris's very own table top sale. Most stuff is junk or horrendously overpriced.

author: binbags
author_rank: Newbie
timestamp: July 10, 2012, 11:08:48 am
content: I agree Simon, but the lack of local electronics shops now, here in the UK, makes one go to Maplins. I can order from long distance, but I like to go into the shop and browse arround.It has been an interesting venture, especially the company in China sending me a free PCb complete.

author: Ian.M
author_rank: Super Contributor
timestamp: September 17, 2024, 04:51:45 pm
content: Deliberately Necroposting!I recently acquired one of these Maplin Precision Gold N16CH (Zhongdi ZD-937) soldering stations. Unfortunately it had a fault - an open circuit heating element, and the tip was in poor condition. However I had on the shelf complete shaft and heater assemblies with the same mounting flange, RS #600-363, for the old RS Components #600-357 or #518-882 temperature controlled soldering irons, which is also a 24V 50W element with thermocouple temperature sensing+ a quantity of various bits for it.The original precision gold iron was wired:1 - white - heater2 - red - thermocouple3 - blue - thermocouple4 - black - heatershell - green - shaft groundAll pin numbers are from the markings on the four pin trailing socket on the lead. N.B. the original element insert's themocouple wires were swapped: red to blue and visa versa in the iron.The RS #600-363 was wired in, blue to thermocouple lead marked B, and the iron reassembled. Unfortunately it ran too hot, melting SAC405 Sn95.5/Ag4/Cu0.5 solder (nom. 217 °C melting point) at its minimum 150°C setting, but it did have temperature control. I concluded the thermocouple must be incompatible.I decided to mod the station. The board was the same as the one in 'binbags' photo post #19 above. The gain of the thermocouple amplifier (dual OPAMP U3) is set by a 68K (R4) : 1K (R3) feedback divider and I determined that increasing the gain by a factor of 1.6 would get me 'in the ballpark'. Rather than replacing R4, I decided to shunt R3 with a 1K5 resistor (to make it easier to reverse the mod in the future), for a gain increase of 1.66. It was then much better behaved and a small tweak of the adjustment pot got it just melting SAC405 with the setpoint at 217 °C.