hybridfree/eevblog-posts huggingface dataset:
Dumpster diving score: 19inch leaking LCD screen worth repairing? - Page 1
Forum section: electronics / repair

author: mianchen
author_rank: Regular Contributor
timestamp: January 26, 2013, 07:41:00 pm
content: got this from a neighbour's skip, it turns on, everything works fine except there is a 4.5 x 1.5 inch blob on the screen. Is it fixable?

author: jaqie
author_rank: Regular Contributor
timestamp: January 26, 2013, 07:42:57 pm
content: big fat *NO*.The LCD screen itself is broken, and those cost as much as the monitor does new to replace, on average. It can be worth it to replace them in a notebook, but that's simply because there's a whole computer in there besides them.If the LCD screen shows any signs of busted, it's scrap.I suggest maybe scrounging inside for some nice spare parts, besides that... it's trash. Sorry.

author: mianchen
author_rank: Regular Contributor
timestamp: January 26, 2013, 07:45:13 pm
content: I think 'no' might be the answer. The 'leaking' blob can be pushed around, but I can't get rid of it after a few minutes of 'massaging'.

author: tom66
author_rank: Super Contributor
timestamp: January 26, 2013, 07:56:29 pm
content: I have seen dark blobs go away after heating but that looks like impact to the panel.

author: mariush
author_rank: Super Contributor
timestamp: January 26, 2013, 09:14:42 pm
content: No.You might be able to sell the power supply board inside and maybe the video board if you keep it on sale on eBay for a few months. But you'd only make 10-20$ after losing a few dollars on eBay fees for relisting it several times.Or you could pull out the power supply and the cfl tubes that are on the sides of the panel and make yourself a lamp (but be careful, the cfl tubes get 700-1400v from the power supply.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 27, 2013, 04:58:26 pm
content: If the rest of the LCD still works, duct tape over the broken part and you might be able to get some use out of it.
theBGAwarehouse Worldwide BGA Repair Tools Distributor - Page 1
Forum section: electronics / repair

author: theBGAwarehouse.com
author_rank: Newbie
timestamp: January 14, 2013, 09:17:05 am
content: Need repairing Bga Rework Station? Need Scotle BGA or any other brands?Visitwww.theBGAwarehouse.comI am the only licensed USA reseller for Achi, honton and Scotle and have exclusive USA rights.Scotle IR6000Scotle IR PRO SCSCOTLE IR360 proZhuomao 5860CBauer IR PRO SCCAchi IR PRO SCMore BGA inventories are available.We sell most all items required for rework/reballing. orders generally take 48 working hours to process with the factory and shipping is 3-5 working days.Our prices can't be beaten. ASK US for forums discount price!user banned - spammer

author: Psi
author_rank: Super Contributor
timestamp: January 14, 2013, 09:27:49 am
content: Quote from: theBGAwarehouse.com on January 14, 2013, 09:17:05 amI'd have to agree there. Most of your products are showing as free ($0.00)I've added lots of them to my shopping cart and the total price with shipping is only $14.99Should i place an order

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: January 14, 2013, 01:01:42 pm
content: Quote from: Psi on January 14, 2013, 09:27:49 amSir ,Some of The Once You do not feel are good please pass them on to me too .Lol

author: tinhead
author_rank: Super Contributor
timestamp: January 14, 2013, 01:26:24 pm
content: Quote from: Psi on January 14, 2013, 09:27:49 ami think to do this as well, they will have to deliver for that price (0 + shipping) what we paid.If not, my lawyer will send them court order.

author: Psi
author_rank: Super Contributor
timestamp: January 14, 2013, 01:37:23 pm
content: I dunno about other countries but in NZ companies don't have to honor advertised prices when the price is obviously wrong.

author: nukie
author_rank: Frequent Contributor
timestamp: January 16, 2013, 07:02:10 am
content: It's virtual product, the items you buy doesn't get shipped but ownership will be transferred to your name. Look it's 0.00kg. It's so nice now we get to own cheap cloud based equipment!

author: tinhead
author_rank: Super Contributor
timestamp: January 16, 2013, 08:15:38 am
content: Quote from: nukie on January 16, 2013, 07:02:10 amheh, you made my day!
Source for pots to repair Tek 2213 - Page 1
Forum section: electronics / repair

author: gooseEL34
author_rank: Regular Contributor
timestamp: February 27, 2013, 09:10:57 pm
content: Hey guys. I need the 5k pot that is used for the intensity on my 2213.Looks to be an Allen Bradley PCB mount.It will be my first update to a piece of my gear.Because it is PCB mount, I am assuming I need an exact replacement to make the pins fit.ThanksTim

author: c4757p
author_rank: Super Contributor
timestamp: February 27, 2013, 09:32:23 pm
content: Don't assume, measure!
follow-up on the leCroy scope repair/troubleshooting - Page 1
Forum section: electronics / repair

author: ConnorGames
author_rank: Regular Contributor
timestamp: November 15, 2012, 04:10:41 am
content: Could you do a follow-up video on the leCroy scope(the broken 1GHz DSO with the CRT)? You have been talking about wanting to make a repair video, and this would be a cool thing to repair. Or did you decide it is unrepairable?Looking forward to the next teardown!

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: December 29, 2012, 11:44:55 am
content: If you haven't already, see #398 and #401... I won't ruin the ending for you.

author: EEVblog
author_rank: Unknown
timestamp: December 29, 2012, 11:48:39 am
content: Quote from: justanothercanuck on December 29, 2012, 11:44:55 am#405 is already uploaded and waiting it's turnDave.
more repair videos? - Page 1
Forum section: electronics / repair

author: mortos360
author_rank: Regular Contributor
timestamp: December 18, 2012, 05:39:12 pm
content: I really like to watch repair videos, especially like the last video form Dave where he explains a bit how to find a short in a circuit.Does any of you know a good youtube channel for such Videos?When ever I try to find some new videos, I always end-up with same list of videos on youtube... mainly the few videos from people like Mike, signal path, Dave, and a few others.Maybe there is not many such videos out there.. or I am just unable to find them... so if you know any good youtube channel or a good video.. please post the link here.Thanks!

author: aluck
author_rank: Regular Contributor
timestamp: December 18, 2012, 06:09:09 pm
content: https://www.eevblog.com/forum/projects/interesting-youtube-repair-channels/

author: Astroplio
author_rank: Regular Contributor
timestamp: December 18, 2012, 06:18:31 pm
content: Some time ago a fellow member (nixxon) posted a video and lead me to subscribe to the repairman/teacher/publisher guy's youtube channel, this is the thread:https://www.eevblog.com/forum/chat/nice-video-tutorial-on-switching-regulator-power-supplies/and this is the guy's youtube channel:https://www.youtube.com/user/randyfrommBrowse the videos he has uploaded, I don't think you will be disappointed; they might be old but IMHO it's quality content.For example, what it was discussed here about the repair Dave attempted on the Lecroy oscilloscope (video #398) thread link:https://www.eevblog.com/forum/blog/eevblog-398-lecroy-9384c-oscilloscope-repair/I had already learned from a teaching video on his channel.Of course there are other more current material out there, I am sure more people will join in and point you to the right direction.Actually, just today I saw a new thread from Amarbir[Lynx-India] the link is here:https://www.eevblog.com/forum/buysellwanted/technical-books-how-to-repair-series-(-worldwide-shipping-english-edition-)/From what the title says it is about books not videos but if you are into it... you might as well check it out!

author: w2aew
author_rank: Super Contributor
timestamp: December 18, 2012, 10:48:44 pm
content: Quote from: mortos360 on December 18, 2012, 05:39:12 pmHave you seen the video I did a few months ago where I debug and repair one of my function generators?

author: mortos360
author_rank: Regular Contributor
timestamp: December 19, 2012, 12:28:41 pm
content: Very nice Video there!! Ill go and check your other videos in a bit.. but I think you have a new subscriber@AstroplioThat guy has some really nice videos, but the video quality is a real plain to watch ^^But anyway.. really nice stuff, gonna take some time to get thru all the videos there...Dave needs a new segment on his show where he repairs stuff!!
Amplifier repair & parts substitutions - Page 1
Forum section: electronics / repair

author: HooRide
author_rank: Regular Contributor
timestamp: November 21, 2012, 10:49:10 pm
content: So I was able to diagnose some problems with a car amplifier I've got on my bench and found (among other things) a pair of MOSFETs that had gone bad (gate and drain were essentially 0 ohms).The parts, IRF540A and IRF9540, are marked as obsolete but I found IRF540NPBF & IRF9540NPBF as possible replacements.My question is, because their specs are not identical, should I replace all parts on both stereo channels to match, replace all parts on one channel to match or just replace what is blown?

author: peter.mitchell
author_rank: Super Contributor
timestamp: November 22, 2012, 04:21:41 am
content: If one side is blown the other side might be on its way out, and at the price of the FETs i'd just replace them both.

author: Tube_Dude
author_rank: Regular Contributor
timestamp: November 22, 2012, 04:42:24 am
content: As the sound quality perception in a car is not so important than in a residential system, added to the noisy environment , I doubt you will find any difference in sound quality between the two channels, if you replace just one pair of Mosfets...

author: Simon
author_rank: Unknown
timestamp: November 22, 2012, 06:50:09 am
content: Quote from: HooRide on November 21, 2012, 10:49:10 pmThe newer parts should work, and yes change them all while you are there.

author: HooRide
author_rank: Regular Contributor
timestamp: November 22, 2012, 08:03:25 am
content: Replace them all I will, they're only $2 and some change each and there are only 8 of them.There are 2 npn/pnp pairs per channel which is why I was worried about mixing as there would be one new and one old pair sharing the speaker load.I'll never know for sure what happened to this amp but it looks as if it tried to ground itself through the RCA inputs as two the two 1n5401 diodes that protect the RCA ground were vaporized as well as the traces and a good part of the PCB is burned.

author: T4P
author_rank: Super Contributor
timestamp: November 22, 2012, 11:25:43 am
content: Hold on a sec with FETs, npn and pnp do not apply, it's the wrong logical explanatory, it's N-channel and P-channelI won't go further but the modern IRF540 and IRF9540 should be a lot better, i have some IRF520s (Old and New, this is the IRF540s brother) lying around and the new ones perform marginally better

author: HooRide
author_rank: Regular Contributor
timestamp: November 22, 2012, 08:06:30 pm
content: Quote from: T4P on November 22, 2012, 11:25:43 amYes, my mistake.I won't go further but the modern IRF540 and IRF9540 should be a lot better, i have some IRF520s (Old and New, this is the IRF540s brother) lying around and the new ones perform marginally betterWe'll see how it goes, I was given the amp for free so at the very least it'll be a learning experience.
Agilent 34410A Repair - Page 1
Forum section: electronics / repair

author: jfedison741
author_rank: Contributor
timestamp: November 13, 2012, 09:07:24 pm
content: Does anyone have familiarity with the repair of either the Agilent 34410A or the 34401A? I am in the process of repairing an Agilent 34410A DMM which is giving faulty readings on 2-wire ohms. All other functions appear to be accurate and stable.When I measure 2-wire ohms I get an offset in the reading. For example on the 100 ohm range I will get readings from 102-110 Ohms in 2-wire mode when measuring a 100 ohm resistor. This same resistor measures a stable 100.0 ohms on a known good meter. In 4-wire ohms mode, the meter under repair gives an accurate stable reading of 100.0 ohms. The current source for 2-wire ohms (100 ohm range) is a stable 1010 microamps on the faulty meter versus 1007 microamps on a known good 34401A.Also, the 2-10 ohms offset appears to drift over time. The same behavior occurs regardless of whether the probes are connected to the front or rear terminals. Multiple sets of probes were used and all gave similar offset. On a known good meter the probe resistance was measured to be 0.2 ohms and stable; multiple probe sets were tried. So far I have checked the relays that switch the signal paths and they appear to be ok (no offset detected across any of the closed contacts). The offset must be coming from elsewhere in the signal path.The unit was purchased new in Nov. 2006. Agilent does not offer repair of this model, they only offer $727 swap of the faulty unit with a refurbished unit.Any help/advice would be much apprecaited!Jeff

author: saturation
author_rank: Super Contributor
timestamp: November 20, 2012, 09:24:39 pm
content: May I suggest you post this request to the HP-agilent yahoogroup, there are more device specific experts there. Both units are still in the Agilent catalog, so I'm surprised they won't repair it, but only swap it.http://tech.groups.yahoo.com/group/hp_agilent_equipment/

author: jfedison741
author_rank: Contributor
timestamp: November 20, 2012, 10:38:16 pm
content: Quote from: saturation on November 20, 2012, 09:24:39 pmThanks for the that link, I will copy my post there.Best regards.

author: free_electron
author_rank: Super Contributor
timestamp: November 21, 2012, 12:25:12 am
content: check the transistor ladder.

author: mzacharias
author_rank: Frequent Contributor
timestamp: November 22, 2012, 01:40:57 pm
content: Trace the input circuit. Any sort of bad or loose connection will cause this and often does not affect voltage readings. Had a very similar problem on my Fluke 8840A. Oxidized push-on connectors at the rear of the input jacks in my case.
Samsung 2233 SN repair  - Page 1
Forum section: electronics / repair

author: DanP
author_rank: Newbie
timestamp: November 01, 2012, 06:15:22 pm
content: Hi all.I have a Samsung 2233 SN which worked ok for a while, then started to show the following symptoms:The colors became washed towards whiteThe contrast became very bad, letters are almost illegible nowWhen you display a black background, the whole LCD panel shows irregular areas going toward whiteWhen it starts up the symptoms are very visible, but after 30 mins or so the displays looks somewhat better (you can watch a movie for example but you have very bad colors, no contrast and so on)The simpotms started from a certain spot on screen and started to "concquer' the whole screen.What do you think guys ?thanks all

author: mariush
author_rank: Super Contributor
timestamp: November 01, 2012, 06:37:31 pm
content: Check the 5v->3.3v and 3.3v/5v -> 1.8v on the display board.
Tek 465B scope repair - Page 1
Forum section: electronics / repair

author: uberblitz
author_rank: Newbie
timestamp: November 03, 2012, 07:29:59 pm
content: Hello,I am sort of stumped trying to fix my Tek 465B scope. It was working fine a few weeks ago but has developed some strange issues as of late.Symptoms:1. With no inputs I get flat lines on both inputs. However, when I turn on scale illumination I get noise on both channels.2. When either input is connected to the calibration output, I see two lines being drawn on the square wave.I have checked the voltage rails on the power supply board, and the +110, +55, +15, +5, and -8 look to be within expected values and are stable.Any ideas on what I should check?

author: grumpydoc
author_rank: Super Contributor
timestamp: November 03, 2012, 08:25:38 pm
content: Power supply lines for voltage and ripple, power supply caps for ESR.

author: uberblitz
author_rank: Newbie
timestamp: November 03, 2012, 10:44:26 pm
content: Well, I think the issue has a lot to do with my bench fluorescent lightsI found that the scope started working right after I turned my lights off. That would explain why I didn't have any issues until a couple of weeks ago with it (that's when I replaced the tubes)SO, that probably means that the main input caps are getting weak and can't filter out that stuff anymore? I don't have an ESR meter (and my dmm doesn't go up high enough to test their capacitance). Any ideas on how to test them?

author: grumpydoc
author_rank: Super Contributor
timestamp: November 03, 2012, 11:12:40 pm
content: You can measure ESR with a sig gen and 'scope - see the noteshere. I suspect the difficulty will be that you don't have a 2nd 'scope.

author: uberblitz
author_rank: Newbie
timestamp: November 03, 2012, 11:18:07 pm
content: I will give that a try. (And I actually have 3 scopes, so it isn't an issue :-)

author: ModemHead
author_rank: Frequent Contributor
timestamp: November 04, 2012, 01:17:47 am
content: Check the grounding contacts for the outer can, make sure they make good contact. Also check all the screws around the vertical attenuator modules for tightness and good contact, especially the shields. The mechanical integrity and grounding around that area is more important than one might think.
Trio/Kenwood CS-1022 Scope Repair - Page 1
Forum section: electronics / repair

author: frampy
author_rank: Contributor
timestamp: October 17, 2012, 09:27:42 pm
content: Hey guys,I acquired this scope at my old job for a bargain. Channel 1 works nicely, but channel 2 only works intermittently. CH2 is being used as the trigger, so there's definitely a solid signal there. I found that playing around with the CH2 invert button sometimes fixes the issue, as you can see in the second image.Does anyone have any ideas about what might be causing this issue? I haven't taken it apart yet. Also, does anyone know where I can find a service manual?Scope faultyScope working - kindaCheers.

author: w2aew
author_rank: Super Contributor
timestamp: October 18, 2012, 02:52:13 am
content: If wiggling the coupling switch (or vertical sensitivity knob, etc.) makes a difference, then the likely causes are either dirty switch contacts or a intermittent/cold solder joints. Neither of these would really require the service manual to address/fix. Careful dis-assembly of the case, and judicious use of a contact cleaner like Caig DeOxit might be all you need. If the switch contacts are open/visible, sliding a piece of isopropyl soaked paper between the contacts will do a nice job of removing oxidation and gently burnishing the contacts. Take a careful look under magnification at any solder joints associated with switches and assemblies that are subject to vibration/movement when used - i.e. where switches mount to PC boards, etc. Look for cracked joints, etc. It's generally not a bad idea to re-solder these connections.

author: frampy
author_rank: Contributor
timestamp: October 18, 2012, 10:19:41 pm
content: Cheers for the info, i'll take a look at the offending switch tonight.I can see how a fualty channel invert switch would cause this if it's a two-pole switch, getting stuck somewhere in the middle.

author: w2aew
author_rank: Super Contributor
timestamp: October 18, 2012, 11:27:26 pm
content: It's not so much getting stuck in the middle, more likely dirty contacts that make them appear open when closed.

author: frampy
author_rank: Contributor
timestamp: November 03, 2012, 07:57:25 am
content: I de-soldered the switch and found that the contact was damaged. I tried to reshape it but It kept bending out of shape after a few presses. So I bypassed the switch so that channel 2 is always non-inverting. Not ideal, but at least I have both channels working now.Thanks for the info. Keep up the good work on your youtube channel too!
My First Video Blog - Repairing a TV - Page 1
Forum section: electronics / repair

author: kolbep
author_rank: Frequent Contributor
timestamp: October 20, 2012, 08:48:10 pm
content: HiThis is my first attempt at a video blog :http://youtu.be/_B_De5c4XlABut since the PSU Capacitor kept on zapping me, it turned more into a blooper reel.Please feel free to comment here or on the video. Does anybody think I would make a reasonable part-time video blogger?Thnkspeter

author: tom66
author_rank: Super Contributor
timestamp: October 20, 2012, 09:04:31 pm
content: I think the heatsinks are live, you are not getting a 400V cap shock, but a 230V / 2 shock (115V) due to live heatsinks. Very painful, but usually only 2.2nF of series capacitance (Y-cap) so low-ish current.

author: kolbep
author_rank: Frequent Contributor
timestamp: October 20, 2012, 09:19:42 pm
content: Nope, it was definately that main cap retaining it's charge (has no bleeder R either).Each time I definitely had the set switched off and unplugged from the mains. The Power cord was also unplugged from the PCB most of the times.P

author: SeanB
author_rank: Super Contributor
timestamp: October 21, 2012, 08:32:33 am
content: First time I would have dead bugged a 1M 1W resistor across that cap................ Been there and gotten belted from old PC psu that had been unplugged for a month, but had open circuit discharge resistors ( and a non working standby power stage to discharge it) on the caps.

author: Jad.z
author_rank: Regular Contributor
timestamp: October 21, 2012, 07:04:30 pm
content: @2:38 You can see a bug heading to your earPS: Please don't get yourself killed

author: kolbep
author_rank: Frequent Contributor
timestamp: October 21, 2012, 07:07:47 pm
content: Well Spotted. I wonder if the bug is still in my ear.

author: Jad.z
author_rank: Regular Contributor
timestamp: October 21, 2012, 07:38:52 pm
content: Quote from: kolbep on October 21, 2012, 07:07:47 pmDon't worry, it must've been zapped dead.

author: SeanB
author_rank: Super Contributor
timestamp: October 21, 2012, 08:12:04 pm
content: Har!
Where have you gotten good deals on used/for repair test equipment? - Page 1
Forum section: electronics / repair

author: ConnorGames
author_rank: Regular Contributor
timestamp: October 07, 2012, 08:08:57 pm
content: As the title says, where have you gotten good deals on used/for repair test equipment? Any stories of crazy deals to make us jealous? Thanks - Connor

author: T4P
author_rank: Super Contributor
timestamp: October 07, 2012, 08:41:29 pm
content: I certainly never used a "text equipment" but test equipmentBut i buy my used equipment locally at sometimes great prices, i saw a fully working FR-803 for 100bucks from them and the next day it's gone!I bet that they don't know the usefulness of something that is why some stuff are extremely low in price even for fully functioning equipment.Here's a list a shop with "PLC" in their company name knows what they sell :VNAs, Audio Analyzers, Oscilloscopes (SADLY!), Power Supplies, Industrial Automation equipmentand that's pretty much what they know ... they have a BUCKETLOAD of random stuff there probably collected from companies going under or a closure of a spinoff company as suchDon't have time to scout for companies going under (Talking as a student with a 8-5 schedule everyday) and that's a remote possibility sometimesI was a bit surprised Dave knew about their ebay shop "buy9.99"

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 08, 2012, 07:27:34 am
content: I just bought a THURLBY LA3200 LOGIC ANALYSER from "buy9.99" gave him a bid, and got it for 25 US$! He got more of them.Clean good unit was in the post just 5 days later.. very good seller.PODs for it, i got around on ebay.Erik
Wanted - Digital Multimeter For USD 200 Max for Repairing Work - Page 1
Forum section: electronics / repair

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 16, 2012, 07:50:51 pm
content: Hello ,I Have a Protek 608 Already .Wanting To Buy Something So That i Have Two To Work On At Two Different Location Benches In Workshop .I Am Open To Old/New Whatever .Have Three Office Torrance/USA , Chandigarh/India And Shenzen /China Hence Please Help .I am very interested in the Agilent U1242B Multimeter

author: psycho0815
author_rank: Regular Contributor
timestamp: September 17, 2012, 06:38:32 am
content: Hi,I recently opened a thread about the same topic. You might wanna have a look.https://www.eevblog.com/forum/beginners/200-$-multimeter/

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 17, 2012, 08:03:22 am
content: Quote from: psycho0815 on September 17, 2012, 06:38:32 amWell,interesting thread there but i have a totally different need for this .My work is related to repairing ,Hence i would prefer capacitance meanrurement till 5000 Micro farads atleast ,Inductance would be a nice addon though not needed ,frequency ,htz and temperature etc etc

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 17, 2012, 03:16:02 pm
content: Well Guys ,I Nailed Another One On Ebay Today ->http://www.ebay.com/itm/280963152622?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649.The Shipping He Says is 20 USD Damn .I have send a email to him to look into this .Though i could keep this also along with the protek i have i can resell it also if you folks think its not a good deal .Well a General discription on manufacturer website "The Model MX55 is a hand-held professional 50,000-count digital multimeter that measures up to the toughest standards. This True RMS (AC or AC+DC) meter provides accurate measurements of non-sinusoidal waveforms. The Model MX55 measures AC Amps, AC Volts, DC Amps, DC Volts, Resistance, Continuity, Capacitance, Frequency and has a Diode Test function. AC Voltage measurement can be displayed in Volts, in dB or in resistance power. Ultra-high input impedance which is selectable to 1G? on the 500mV range. Built into a rugged housing which provides a separate battery and fuse compartment to isolate the DMM's electronics from contamination. The Model MX55 is waterproof, IP 67 rate as well as CE marked."PDF Datasheet - >http://www.aemc.com/products/pdf/2116.71.pdf
Terrible Experience - Repairing a No Name Chinese Inspection Magnifier   - Page 1
Forum section: electronics / repair

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 18, 2012, 07:55:18 pm
content: Guys ,On Saturday night i forgot to switch off my main inspection magnifier on my main desk .As dave says tanaaa in the next morning i had a sunday blue hee hee instead of monday .This thing would not switch on horrible .Hence opened the same up and on inspection i saw one of the caps 10 microfards 250 volts from a stupid nitron brand company had blown up "Leaked from top actually " .Hence i took them out of circuit and got two replacement BC Philips i think Caps and installed them .Just before i switched the same on i though lets check other components .Well tested one MJE13003 Leaky "Transistor " .Got two replacements and Bammmmm whats going on .Upon testing i saw that the base is actually on the left side and mine older once were on the other side "What" .I checked the datasheet and i confirmed that yes my base was actually on the wrong side .Fake chinese MJE13003 ? No idea ,I reversed the new MJE13003 and started the board Tannaaa everything worked fine "Though the CCFL was also replaced the older one was busted " .Hence always use your multimeter to check if its no name chinese anything is possible .This lamp has served me everyday use since 10 years plus and its fit now for another 10 i hope .

author: G7PSK
author_rank: Super Contributor
timestamp: September 18, 2012, 08:08:47 pm
content: Ten years already. Thats not bad for an electrolytic in the general scheme of things. In fact that's good, and one cannot complain about such service, some of these caps don't last ten minuets.

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: September 18, 2012, 08:12:53 pm
content: Quote from: G7PSK on September 18, 2012, 08:08:47 pmWell,Very Very Less used in this time .Just started using this since april 2012 aggressively .The complaint was about the "No idea fake " MJE13003 in reverse .

author: SeanB
author_rank: Super Contributor
timestamp: September 19, 2012, 03:40:21 pm
content: I often just take another CFL lamp and use the electronics as a replacement unit. Often cheaper than the spares, and likely to last longer as it will run cooler in this application.
Repair of HP 5245L Electronic Counter (with Nixie tubes!) - Page 1
Forum section: electronics / repair

author: Lupin III.
author_rank: Contributor
timestamp: August 26, 2012, 01:13:48 pm
content: Hi!I've got an HP 5245L Electronic Counter, which no longer works as it should. Because it was standing around unused for quite some time I started it up slowly with a variac. The funny thing is, when setting the variac from something between 150V to 180V the counter works and the internal crystal reference produces it's 1MHz signal that is countable with the counter. But if I go higher, everything up to the nominal 230V the counter stops working.I checked the voltages from the powersupply. At 150V to 180V they are of course all too low and way out of spec (still the thing works) and at 230V they are all pretty accurate and stable (also checked with oscilloscope), but the counter will NOT work.I'm now pretty much at a loss what to do next. I have got two service manuals, but they are for later versions of the counter (for serial prefixes of 628- and 716-), while serial prefix 605- (which my counter has) should be described in the manual for serial prefixes 544-. Unfortunately the circuit boards seem to have changed quite a lot between the versions (not only the layout, but even the parts count), so except for the power supply voltages, theres was not much I could use from the newer manuals.Can someone help me find the right service manual? Even though this device is over 50 years old, it would be a shame to scrap it. Even if it's just to save the Nixie tubes!
Repaired - Digitron T208 Thermocouple meter - Page 1
Forum section: electronics / repair

author: tom66
author_rank: Super Contributor
timestamp: August 25, 2012, 08:17:20 pm
content: Got it free from work, they give me lots of nice broken stuff.It had a common LCD issue. Problem was half the segments were not visible, the other half dim or fully visible.Tore it down - very difficult as it is completely sealed. Had to cut open at the only exposed edge and unbolt the battery hookups (9V) - the connector connects through some bolts. I guess it is designed for factory environments with a lot of dust and particulates, or maybe even brief submersion? I did not care about that, I just wanted a nice accurate thermocouple meter.So, I tore it down to reveal the circuit board. Immediately, I saw the problem: the zebra strips were bent. I loosened the LCD bolts, reseated the zebra strips, and that fixed it.Second issue was I had no thermocouples with the standardised connector. I -did- have one with banana plugs. So I cut the leads off, and soldered them to the PCB.Free, very high accuracy thermocouple meter. Lots of uses for this one - will replace my IR thermometer for most uses.Suspect the OEM to be "AET", unit is made in England.
LCD inverter repair/mod - Page 1
Forum section: electronics / repair

author: Psi
author_rank: Super Contributor
timestamp: August 31, 2012, 02:42:58 am
content: I have an old 17" LCD that works for about 2 seconds then turns off.I tracked part of the problem down to a couple of dead flyback driver transistors on one of the backlight inverters.I don't really want to wait 2 weeks to order some new parts and have a need to get it running this weekend.I also don't have any transistors fast enough to hack up a replacement for the dead transistors.So i figured it would be easier to just bypass the non working inverter since the LCD is bright enough with only one backlight working, but i need to solve the issue of it switching off after 2 seconds.At first i thought it was just a feedback issue and the IC was shutting both inverters down when it didn't get one of the feedback signals, however i've bypassed that and it still wont stay on.(It's a dual switchmode controller IC, TL1451http://www.ti.com/lit/ds/symlink/tl1451.pdf)So now i'm wondering if the design of the IC makes it impossible to run only one side of the chip.Can anyone see if that's the case or not?I'm also a little unsure how they are controlling the backlight brightness with a capacitor in series with each feedback input.Here is the circuit diagram of the LCD inverter boardThe top half is running and displays a picture for 2 seconds or so, its the bottom have that blew up and seems to be still causing issues.I have removed the shorted fets and checked all the power rails, it's definitely the chip shutting itself off.And the switchmode IC diagram

author: amyk
author_rank: Super Contributor
timestamp: August 31, 2012, 05:35:30 am
content: Each half is a buck converter driving a Royer oscillator. The brightness input controls the output voltage of the buck converters, with current feedback coming from the secondary (sense resistors R232 and R233) and phase from the primary (voltage dividers R220/R222 and R221/223). You can cut the feedback from the 2nd half and connect it to the 1st half so both sides will stay in balance and on, like this:

author: Psi
author_rank: Super Contributor
timestamp: August 31, 2012, 06:16:58 am
content: I tried linking the non-working feedback to the working side with no luck. But i didnt try linking the DTC at the same time.Thanks, ill try that and see if it fixes the issue.
Tek 465B BNC repair - Page 1
Forum section: electronics / repair

author: adauphin
author_rank: Unknown
timestamp: August 10, 2012, 03:03:07 am
content: My first post and I found this site on a 465 restoration by ModemHead...great job BTW.So I picked up a 465B and it seems the CH2 BNC is loose. I pulled the case and found out that the diode (looks like a resistor) is not attached and there is a fine wire leading away from the BNC. This is my first scope and my gateway to diagnosing electronics beyond what my DMM can accomplish.Seems like a simple solder fix, if anyone has a pic of one conected the correct way that would be a great help. Late here so I will try to get a pic tomorrow. Looks like there is a polyswitch in there also...kinda cramped but I think I can get to it ok.Looking forward to being a part of the community.

author: FenderBender
author_rank: Super Contributor
timestamp: August 11, 2012, 12:54:47 pm
content: Well the shell of the BNC should be mains earth referenced. So as long as the shell comes in contact with the metal case, it should be right.The center pin of the BNC should be connected to a board via a bare piece of short piece of wire or resistor. I don't think it could have been a diode. You would surely chop your waveform?

author: adauphin
author_rank: Unknown
timestamp: August 13, 2012, 12:45:26 am
content: After removing the metal guards over the adjustment screws, I realized it was a resistor..had flat ends so It looked to be a diode. Definately a tight squeeze in there, seems to be OK now.
Repairing a HP 6227B power supply - Page 1
Forum section: electronics / repair

author: Nirios
author_rank: Regular Contributor
timestamp: August 01, 2012, 04:35:18 pm
content: I recently acquired a HP 6227B power supply. The supply itself is in great condition except for the beating it took from UPS during shipping. Making a power supply frame out of aluminum is great for heat dissipation, but not great for keeping its shape. I have bent the major parts of the frame back to near square, but one of the supply boards cracked its connector. The contacts do not appear to be broken, however the crack widens when the card is inserted into the connector. I was wondering if I could use super glue or another adhesive (in very small quantity) to repair the crack.See images here:http://imgur.com/a/8oBXv

author: SeanB
author_rank: Super Contributor
timestamp: August 01, 2012, 06:18:55 pm
content: A drop of superglue when the card is in followed by removing the card to close the gap, and leave for 24 hours in a warm area to cure the superglue. Use a good quality one, like the Locktite brand.

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 01, 2012, 06:50:40 pm
content: Looks like the PCB has enough space to mount something next to the connector as a support, drill a few holes and screw something on to help the connector keep closed, after you glued it of course. Those cards look pretty heavy...

author: Short Circuit
author_rank: Frequent Contributor
timestamp: August 01, 2012, 08:34:41 pm
content: In addition to glueing (carefull not to contaminate the contacts), I would probablycreate a small U-shaped brace to support the plastic from the outside. Perhaps fromaluminium or just some FR4.
Looking for wiring diagram & repair of BK 1635 power supply ? - Page 1
Forum section: electronics / repair

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: July 17, 2012, 12:48:44 pm
content: I got this free , a BK 1636 PS , it had the Neg. post broken off , put on in from my parts bin .I power it up and it seem to work OK , till I turn up both the course & fine pots , at about 4v it will jump to 43v , the max is spouse to be 30v at 3a .Have to power down to reset , then the same again .My diagnostic skills are not enough yet , especially with out a wiring diagram .Any help ?Thanks John

author: Simon
author_rank: Unknown
timestamp: July 17, 2012, 12:58:56 pm
content: maybe the pot track is broken. The pot is part of the feedback circuit so it sounds like the full unregulated voltage is allowed through.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: July 17, 2012, 01:06:13 pm
content: That is one of ideas that has been suggested , also a pass transistor , not sure which transistor that would be .Still looking for a wiring diagram , downloaded the manual , but not in there ?I will have to put my meter to the pot and see if that checks out .Thanks

author: Simon
author_rank: Unknown
timestamp: July 17, 2012, 01:26:54 pm
content: surely if it was the pass transistor it would do it all the time. the fact that that is happens on a certain setting makes me think the pot (I actually had this problem with my car throttle once). You say the socket was broken, sounds like it was hit which may have damaged the pot too.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: July 19, 2012, 04:08:28 pm
content: I pulled both the fine & course adj. pots , they have the same number on them .The course was the one that seemed to make the meter malfunction , but testing showed that fine adj. pot has an open circuit .Have found a match for replacement yet .
EEVblog #295   PLZ help me to repair this Ebook reader - Page 1
Forum section: electronics / repair

author: Ranatungawk
author_rank: Newbie
timestamp: June 25, 2012, 03:45:09 am
content: I’m writing this expecting a troubleshooting advices from you to fix my Chinese eBook reader, which is exact similar to the eBook reader you discussed in “EEVblog #295 - $30 eBook Reader Teardown”. I spent $47 for this. Even though it’s a small amount in ur country, it’s a somewhat big amount for a guy who live in a developing country—like me : -) So I hope that you will put your kind attention on this ..Problem:I used this Ebook reader since 4 months. Recently I charged it and forgot to stop charging until 12 hr. after 12 hr. I removed it from the charger. Till then, it cant be turned on (no power at all, it’s dead). One or two times it came up but after 1min got down again. However, now it doen’t come up at all. Then I opened the ebook reader and removed the battery and kept 1or 2hr and tried to ON, but it’s still dead. When I connect the ebookreader to the charger, I found SS14 diode, which is at PT1502, get heated.!!What I have done so far..:According to the data-sheet of PT1502, as far as I could understand, when power button is pressed 3v-5v signal should come to the PT1502 in order to turn on the CPU. However, when I check, I found voltage on the above pin is around 2.51v. Can this be a reasonI identified this voltage come to PT1502 through a SMD type SCHOTTKY DIODE (KL3). When switch is off, 4.07V come to the switch, but it’s dropped 2.51 when button is pressed.First I thought it was a faulty of PT1502 or SS14. So I replaced the both items with new ones. But the issue remains same.So can you please give me a advise to fix this ?
Repair project - Instek GPS-3030 Power Supply - Page 1
Forum section: electronics / repair

author: deathventure
author_rank: Newbie
timestamp: June 03, 2012, 04:15:02 pm
content: I got a hold of a an Instek GPS-3030 power supply for 5 bucks. There's a problem with the output. I've tracked down an issue where a 15 volt regulator and a TIP32C transistor are overheating, so there's probably a short somewhere. I'm wondering if anybody would be able to help find a service manual for me, or a schematic of the board. I've scoured google for the past day or so looking for one, but still came up zip. This particular power supply also goes under the models Protek - 305L (analog dial) and the Tenma 72-2010. Thanks!

author: MikeK
author_rank: Super Contributor
timestamp: June 03, 2012, 04:37:42 pm
content: The manual on their website has a block diagram, which should be at least somewhat helpful. I would email them ask and tell them how much you like it, but you need the schematic to fix this little problem.

author: T4P
author_rank: Super Contributor
timestamp: June 03, 2012, 06:28:50 pm
content: Quote from: deathventure on June 03, 2012, 04:15:02 pmThe protek is a rebrand and the Tenma is a clone.
Metex M-3610 repair help - dmm won't zero properly in ohms and DC volts  - Page 1
Forum section: electronics / repair

author: retiredcaps
author_rank: Super Contributor
timestamp: March 12, 2012, 04:44:20 am
content: I got this Metex M-3610 for free. It looks like it was made in 1987.Unfortunately, it doesn't zero when I touch the probes together on DC voltage. It reads about 0.250Vs when the probes are not touching. When I measure a 9V battery, it reads 0.63V even though it is a new battery.On resistance mode, the multimeter correctly shows "1" or out of range when the probes are not touching, but when I touch the probes together, I get 25 ohms.I have tried known good probes and fresh akaline batteries so I'm sure the problem is with the M-3610 itself.It uses the IC7106 chip and in the datasheet athttp://pdf1.alldatasheet.com/datasheet-pdf/view/177757/INTERSIL/ICL7106CPLZ.htmlit talks about AN032 "Understanding the Auto-Zero and Common Mode Performance of the ICL7136/7/9 Family", but for the life of me, I cannot find the datasheet/app note anywhere.I'm assuming my problem is with the auto-zero function, but without the app note, I'm not sure what exactly to test.Suggestions would be appreciated. I know this multimeter isn't worth much, but I want to learn more about electronics and this is a great opportunity.PS. Now I know why Dave Jones hates those 9V wires. I managed to damage the red wire when snapping back the case on. I didn't see it trapped between the case and screw hole when I put the front cover back on.

author: amyk
author_rank: Super Contributor
timestamp: March 12, 2012, 11:02:20 am
content: That looks like the ancestor of the infamous DT-830 series.Apart from checking to see if any components have drifted out of spec, the only other culprit is the '7106 itself.

author: retiredcaps
author_rank: Super Contributor
timestamp: March 12, 2012, 12:19:44 pm
content: Quote from: amyk on March 12, 2012, 11:02:20 amYes, I had the same thought when I saw the 7106 chip. At least I have your Elenco kit instruction manual allow with the 7106 datasheet to give me some idea how it works.QuoteWell, there aren't too many components so I guess I will start checking in circuit first and anything that looks suspicious will warrant desoldering and retesting out of circuit.Thanks again for your input. It is appreciated.

author: retiredcaps
author_rank: Super Contributor
timestamp: March 30, 2012, 05:29:41 am
content: FYI. More rebadged dmm!! Saw this thread and watched the video.https://www.eevblog.com/forum/general-chat/fake-transistors-!-never/I noticed that the SkyTronics 600.527 is identical to the Metex M-3610 (made in 1986).

author: wkb
author_rank: Super Contributor
timestamp: March 30, 2012, 05:58:49 am
content: That is the same multimeter as one in my collection. Mine still works just fine btw.
Ground breaking device for track repair! - Page 1
Forum section: electronics / repair

author: iamwhoiam
author_rank: Contributor
timestamp: April 20, 2012, 03:11:25 am
content: This is ground breaking stuff for track repair:

author: metalphreak
author_rank: Frequent Contributor
timestamp: April 20, 2012, 05:19:05 am
content: A picture of a jackhammer from a jackass

author: david77
author_rank: Frequent Contributor
timestamp: April 20, 2012, 06:30:10 am
content: Come on people, don't be so grumpy.This is what I call track repair:Now, how many amps could a track like that carry?

author: siliconmix
author_rank: Frequent Contributor
timestamp: April 20, 2012, 08:02:32 am
content: are all the sections physically joined.there might be a few shorts

author: Rerouter
author_rank: Super Contributor
timestamp: April 20, 2012, 03:33:50 pm
content: In australia the tracks are used for a negative return, and also for signalling (as the axel of the train shorts one side to another it is used to trip a relay or similar)edit: still a dick move for a thread

author: G7PSK
author_rank: Super Contributor
timestamp: April 20, 2012, 04:03:19 pm
content: They are the return on mainline here in the UK overhead pick up at 11KV or so and neutral on the rail which is why they all have to be bonded.

author: Time
author_rank: Frequent Contributor
timestamp: April 20, 2012, 04:39:51 pm
content: In all seriousness:I use a metal engraver to cut my traces when needed. Works well and makes a nice neat little etch.
dirt cheap 34401a on ebay for repair $185 USD - Page 1
Forum section: electronics / repair

author: benemorius
author_rank: Regular Contributor
timestamp: February 20, 2012, 09:12:23 pm
content: http://www.ebay.com/itm/Agilent-HP-34401A-DMM-6-1-2-READ-/280829798112?pt=LH_DefaultDomain_0&hash=item4162c2a6e0#ht_500wt_1413Someone just posted a group of these meters as buy it now and this is the only one still left. It won't be around much longer at this price even in its broken state, so here's hoping it goes to someone who needs it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 20, 2012, 09:27:38 pm
content: I have a PDF of the service manual for this if anyone needs it.

author: Mint.
author_rank: Frequent Contributor
timestamp: February 21, 2012, 01:00:47 am
content: Anybody got any idea on how to repair this?

author: Bored@Work
author_rank: Super Contributor
timestamp: February 21, 2012, 01:09:50 am
content: Quote from: Mint. on February 21, 2012, 01:00:47 amYou fix every problem you encounter.

author: damo
author_rank: Contributor
timestamp: February 23, 2012, 01:05:57 pm
content: Ended. But seems to be back again on a different listing with auction enabled. 0 bids as of writing with $100US as reserve. Wish I had the $$$.http://www.ebay.com/itm/Agilent-HP-34401A-DMM-6-1-2-READ-/280831267664?pt=LH_DefaultDomain_0&hash=item4162d91350

author: aluck
author_rank: Regular Contributor
timestamp: February 23, 2012, 06:19:43 pm
content: Quote from: damo on February 23, 2012, 01:05:57 pmWish they ship to Russia.

author: wkb
author_rank: Super Contributor
timestamp: February 23, 2012, 07:43:49 pm
content: You know what annoys me like hell: I had a couple of these bench meters but did not know what to do with them in those days. So I gave them away. Pretty sure they ended in the skip..