hybridfree/eevblog-posts huggingface dataset:
Unknown SMT device 2Q - Page 1
Forum section: electronics / repair

author: artag
author_rank: Super Contributor
timestamp: November 04, 2018, 02:24:21 pm
content: I've got a board with a couple of 6-pin SMT devices. They're marked 2Q and on the second line ow34 - the o is offset and might be a logo, or a pin 1 marker.I can't find it in the SMD code book as 2Q (the only 2Q is a SOT32), but as 34 it could be a MUN5334DW1 complementary bipolar digital transistorhttp://www.onsemi.com/pub/Collateral/DTC124XP-D.PDF.That would make sense circuit-wise too - it's used as a power output stage, like a class AB amplifier.The markings don't seem to add up though. If it were the On Semiconductor part it should be marked 34M. (the . is part of the marking, meaning lead-free). Could it be a second-source ? or some other part entirely, such as a mosfet half h-bridge, which would also make sense in the circuit ?
Thandar TG105 Service Manual - Page 1
Forum section: electronics / repair

author: john2183
author_rank: Newbie
timestamp: December 05, 2016, 12:52:13 pm
content: Hello,Does anyone have a pdf copy of the Thandar TG105 workshop (service) manual, cannot find a copy on the web.Kind regards, John.

author: Eb2aoc
author_rank: Newbie
timestamp: October 28, 2018, 09:54:31 am
content: Hello,Sorry for recovering this old topic, but I'm also in the same situation. Looking for this manual and cannot find anything on the web.Something knows something about it??Thanks in advance.Best regards, Javi

author: coromonadalix
author_rank: Super Contributor
timestamp: October 28, 2018, 08:17:23 pm
content: Maybe the tg-102 has some similarities ?https://www.kevinchant.com/uploads/7/1/0/8/7108231/thandar_tg-102-workshop-manual.pdf

author: Eb2aoc
author_rank: Newbie
timestamp: November 04, 2018, 10:29:16 pm
content: Bi Coromonadalix.Many thanks for your replay. The TG-102 is a Function Generator and I suposse that it will be more complex, but may be with some similarities.....I will give a try to your suggestion, will open the covers of TG-105 and will be looking for those similarities with TG-102.Best regards
Delete - Page 1
Forum section: electronics / repair

author: KG7AMV
author_rank: Frequent Contributor
timestamp: July 01, 2018, 09:20:10 pm
content: Deleted

author: Cyberdragon
author_rank: Super Contributor
timestamp: July 02, 2018, 09:50:27 pm
content: "doesn't look" may not be good enough, they could still be fried internally. Diode test them for shorts. The transistors look like the only thing high enough power to blow up that large resistor without blowing themselves up.What is that component on the transistor and diode rack third from the bottom right with 5 leads?

author: coromonadalix
author_rank: Super Contributor
timestamp: November 03, 2018, 03:04:04 pm
content: Glad it worked, what a complicated way to add multiple heat dissipators, why they did not use an plain single one ? tons of manufacturing processes and costs ? and they snap onto the transistors pfffff
Unknown soic8 - Page 1
Forum section: electronics / repair

author: salviador
author_rank: Regular Contributor
timestamp: November 01, 2018, 11:13:50 am
content: Hi , What component is this?AUE4AX3

author: wraper
author_rank: Unknown
timestamp: November 01, 2018, 11:56:02 am
content: This is not SOIC, looks more like TSSOP. Pin pinch distance?https://www.infineon.com/cms/en/product/packages/PG-TSSOP/PG-TSSOP-8-1/

author: branadic
author_rank: Super Contributor
timestamp: November 02, 2018, 08:58:34 pm
content: It's MSOP8. Package Marking "AUE" delivers OPA727.-branadic-

author: salviador
author_rank: Regular Contributor
timestamp: November 03, 2018, 01:25:31 pm
content: thanks, so it's an opamp, I can replace it with an OPA727 ?

author: wraper
author_rank: Unknown
timestamp: November 03, 2018, 02:19:39 pm
content: Quote from: salviador on November 03, 2018, 01:25:31 pmIt is OPA727, you can google for pictures how it looks like. But why did you decide it's faulty to begin with?
I need diagram schematic tv plasma LG 50PT250B - Page 1
Forum section: electronics / repair

author: eletmoraes
author_rank: Newbie
timestamp: November 02, 2018, 12:50:22 am
content: I have the YSUS board of this tv that the zener diode Z201 has exploded . And the t-con card of the tv, before the chip IC201 presented a heating that for me considered abnormal.CODE BOARD POWERPCB: EAX63329901/11 PSU P/N: EAY62171101
Tek 2465BCT CRT date codes - Page 1
Forum section: electronics / repair

author: NHnewbie
author_rank: Contributor
timestamp: November 01, 2018, 07:29:02 pm
content: I have recently acquired a spare CRT for my 2465BCT and am trying to understand the markings as follows:P/N?: 154-0850-01S/N?: 149403Other?: 41-91 Is this possibly a date code, perhaps corresponding to week 41 of year 1991? If not, is there another meaning?This CRT is used and I have no idea how much use it has had. In any event, seller described as "tested, working" and the price was right.Thanks,RickK8EZB

author: Gyro
author_rank: Super Contributor
timestamp: November 01, 2018, 07:37:06 pm
content: Why double post when you already have a current thread about this CRT?https://www.eevblog.com/forum/testgear/tek-2465bct-question/msg1933507/?topicseen#msg1933507

author: NHnewbie
author_rank: Contributor
timestamp: November 01, 2018, 07:58:03 pm
content: QuoteNewer post, somewhat different topic.

author: Gyro
author_rank: Super Contributor
timestamp: November 01, 2018, 08:04:35 pm
content: They are both related to your Tek 2465BCT CRT(s), you could simply have asked it as a supplementary question in the thread that you had just posted a reply in.Not a big deal but you already had a tuned in audience on that one.

author: NHnewbie
author_rank: Contributor
timestamp: November 01, 2018, 08:14:29 pm
content: QuoteApparently a big enough deal for you to notice and make two responses. I am not a Super Contributor like you, as can be seen from my very small number of posts, so not yet aware of the unwritten rules here. I'll try to be more careful in the future.

author: Gyro
author_rank: Super Contributor
timestamp: November 01, 2018, 09:18:50 pm
content: Hey, no offence meant, it really isn't a big deal - although it's useful to be aware that people round here do tend to be sensitive to double posting. None of us started out as super contributors you know (there's no way to avoid the title). When I read your OP I failed to notice that you were talking about a second CRT, not the one you already had in your 2465BCT.With reference to your actual question, Tek can be a bit cryptic at times but it's quite feasible that it is a straightforward datecode - the scope was introduced in 1984.
Analog VU Meter - Page 1
Forum section: electronics / repair

author: vidarr
author_rank: Frequent Contributor
timestamp: October 31, 2018, 11:50:41 pm
content: This VU meter came from an audiometer my wife found the other day. This would go great with the amp circuit I built a couple weeks ago. I took it out and am trying to test it, but I am getting nothing. I am using a 3.5mm audio jack to the VU meter from my computer. I tried different combinations from the jack to the two terminals on the meter. There doesn't appear to be anything wrong with the meter visually looking at it.Do I need to open it up to fix something? What should I look for now?Thank you!

author: BradC
author_rank: Super Contributor
timestamp: October 31, 2018, 11:54:24 pm
content: Yeah, that won't work. The meter will need a rectifier and amplifier to generate a correctly proportioned DC signal to drive the coil.

author: floobydust
author_rank: Super Contributor
timestamp: November 01, 2018, 12:09:21 am
content: An analog meter needs DC not AC, but your picture shows a mystery 4-pin black part which I think is a bridge rectifier. So the meter would be fine with AC coming in, but would do nothing and not move until >1.5V is present. You could test with a multimeter, or just turn up the volume.

author: vidarr
author_rank: Frequent Contributor
timestamp: November 01, 2018, 12:50:41 am
content: Quote from: floobydust on November 01, 2018, 12:09:21 amYes. The multimeter worked. It sent the needle to max.This whole circuity for the audiometer is AC and DC. There is a transformer off the mains. There is no bridge rectifier right there, just a 12v LM340 voltage regulator. It seems each piece of the circuitry has its own bridge rectifier (or not).Thank you again!edit: I forgot... When I connect this to my amp circuit I will put it on one of the lines out to the speakers (its a stereo amp). Will the VU meter need an additional 1.5v supply? If it does, does it go to the terminal marked "+", or the blank one? I was reading on some music forums and it seemed everything they did was reversed. Like they put the ground to the "+".

author: floobydust
author_rank: Super Contributor
timestamp: November 01, 2018, 01:15:57 am
content: Try the multimeter with both polarities, the meter should move up either polarity if there already is a rectifier inside the meter's case (the little black cube).Don't connect it directly to speakers, the signal is too strong. You need a resistor to lower it, depending on what volume you want to be full-scale. I would try 3k-10k ohm resistor in series.

author: vidarr
author_rank: Frequent Contributor
timestamp: November 01, 2018, 12:54:47 pm
content: Quote from: floobydust on November 01, 2018, 01:15:57 amOK. Thank you for that advice.I was also wrong about the bridge rectifier(s). I was wondering if AC current could go into the LM340 voltage regulator and maybe not right? I took the main board out today anyway and found I think a bridge rectifier buried in the corner in circuit before the LM340.Thank you.
Fluke 8842A Relay K301/K401 - Page 1
Forum section: electronics / repair

author: omegaone
author_rank: Contributor
timestamp: October 13, 2018, 03:14:02 am
content: Previous issue with a Blank Display and VFD replaced. Now the display comes on but flickers and goes off.Suspect relay K301/ K401. If anyone has more info on these particular relays (they used to be active when power is turned on, now they are quiet) and their function please let me know.Part Number:AZ7-2C-5DE (mechanical relay)R8378-1 (reed relay)Relay K301 coil checked to be ok (about 90 ohms) and activates with 5 VDC from external input.No power to the relay when the start button is pushed.Micro controller U201 pins 1-9 all have 4.8 VDC available but pin 18 and 19 which is supply power to the relay does not have power.Continuing my troubleshooting with my limited knowledge. If anyone can offer any feedback on my findings please comment!

author: mzacharias
author_rank: Frequent Contributor
timestamp: October 14, 2018, 01:33:27 am
content: My 8840A (same model, basically) had the same problem and it was solder connections associated with the power transformer.They didn't look bad either, but re-soldering them fixed the issue.

author: Moonbase
author_rank: Contributor
timestamp: October 31, 2018, 03:56:21 pm
content: Quote from: omegaone on October 13, 2018, 03:14:02 amJust by chance, got a source for the good old Noritake Itron CP2067A VFDs?

author: omegaone
author_rank: Contributor
timestamp: November 01, 2018, 07:16:55 am
content: Best person to query would be Ordinaryman1971. He helped me procure 8842A VFD.All the best!
Today's excursion, maintance tips - Page 1
Forum section: electronics / repair

author: TiTanerCZE
author_rank: Contributor
timestamp: October 31, 2018, 09:31:27 pm
content: On today's school excursion in a production. I dont know, but every time we have exursion I see a lot of dirty machines.Today I have seen a reflow soldering. Some parts were so dirty from a flux that even a IPA wasnt enough, are thay some special cleaning agents or its just not possible to remove? How can something like that even happen? Is it normal?Do not know if its just a bad practice? Can you give an info on how it should be done?

author: ataradov
author_rank: Super Contributor
timestamp: October 31, 2018, 09:50:39 pm
content: Production is always reasonably messy. There are some steps you can take to make things cleaner, but if you are dealing with chemicals, it is hard to keep things pristine. It all depends on what you have seen exactly, hard to tell how good or bad it is without pictures.The best you can do is completely surround the machine with a case, which will contain the dirt inside. This works well for CNC machines. But this does not work well for PCB manufacturing, since it is typically organized as a series of processing steps.There are clean rooms for IC manufacturing.They are as clean as it gets, but nobody will let a school excursion into one of those. At most you will see things though windows, and won't get a good feel for anything,
LG E400 no boot, totally dead - Page 1
Forum section: electronics / repair

author: panoss
author_rank: Frequent Contributor
timestamp: August 20, 2018, 02:09:54 pm
content: I have an LG E400.It does not boot, it doesn't do anything, dos not react to anything.I press the on switch, nothing. I plug in the usb charger, nothing.Battery is charged.The on-off switch works fine.Visibly, no part looks burnt.Any hint is welcome (or service manual of E400 or similar model).

author: panoss
author_rank: Frequent Contributor
timestamp: October 30, 2018, 08:19:25 am
content: Ok, back to this old LG phone (I know it 's an old practically useless phone but my goal is self 'educational').I 've found the service manual.You can get it from here:https://www.manualslib.com/manual/1227017/Lg-Lg-E400.htmlClick the 'Download' green button on top left. Then tick the box in the Captcha 'I 'm not a robot' and answer on the related question that proves you 're human.And then click on 'Download PDF'.When I connect it to USB power supply it draws 340mA.This is with the battery in the phone. I suppose it's charging the battery.Battery voltage is at 3.8V.When I press the power on button, nothing happens: does not vibrate, no light, nothing. And the current draw remains unchanged at 340mA.I used the service manual:Service manual, page 92, 4.10 Power on Trouble Shooting:Voltages at test points are correct(these voltages appear after pressing the power on button):VREG_MSMC1_1.1V (L400),VREG_MSMC2_1.1V (L401)vREG_MSME_1.8V (L402),vREG_P3_2.85V (c453),VREG_MSMA1_2.6V (C448),VREG_MSMA2_1.2V (C444),VREG_TCXO_2.85V (C449)Next step is to check the clock butI cannot, I have no oscilloscope.Service manual, page 144: According to the block schematic:vibrator is connected to PM8029 IC (Power Manager chip). And gets activated by this. So, the fact that itdoes not vibrate at all, means the PM8029 is faulty?So, my question is: is there some way to check PM8029 so that I 'll be sure 100% if it works or not?

author: t1d
author_rank: Super Contributor
timestamp: October 31, 2018, 09:38:51 am
content: Don't forget to check YouTube, for your make and model and general problem. They have rather decent repair videos.

author: panoss
author_rank: Frequent Contributor
timestamp: October 31, 2018, 10:44:24 am
content: I watched a few but none of them helped.Thanks anyway!
Stag ZL30/ZL32 information - Page 1
Forum section: electronics / repair

author: guido
author_rank: Regular Contributor
timestamp: October 31, 2018, 10:53:16 pm
content: I have two ZL30A programmers which I am trying to repair. They can handle Signetics 82S1xx devices. One of them passes the self test and talks to the DOS program. But when trying to read a 82Sxxx device, there are no supply/program voltages present on the specific socket (and the problem is not a connection problem from socket to main pcb). I have the operator manual, but unfortunately this is without any schematics. It is quite a complicated 4 layer board and not much is socket-ed. And there are a lot of components. Number two has more problems and i cannot keep it switched on for at moment to compare (a resistor in a driver circuit gets too hot and no display).I found four test points on the board. One to three give 5V, number four 0V on the first programmer. Bit suspicious, but i think these voltages change according to the specific device and operation (looks like they are generated by a number of DACs + driver circuits).Would be great if anyone has any info on these things, which could help me fix them. I know about Matthieu Benoit's site, the latest ZL30A addition on it comes from meThanks,Guido
Old transistor replacement for Fronius Transarc 500 (Castolin Transmodul 500) - Page 1
Forum section: electronics / repair

author: dziacial
author_rank: Newbie
timestamp: October 29, 2018, 11:46:06 am
content: Can anyone help me find replacement for old ESM2893V transistor. It was used in Froniu Transarc 500 (Castolin Transmodul 500) welder. It look like this:Maybe someone have service manual for this welder?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 30, 2018, 10:24:00 am
content: They where used in arc welders = NPN power darlington 28v at 93 ampsI think sgs thomson have equivalents ??They were similar to ESM2030DV on another thread, some one had 14 of them to sale in 2008 ? or an esm 3045dv as a substituteOnly links ive found :http://www.sabaelec.ir/products_new.asp?groups=315&gname=ISOTOP%20Transistors&mname1=Transistors

author: coromonadalix
author_rank: Super Contributor
timestamp: October 30, 2018, 10:27:44 am
content: Mouser have this pdf :https://www.mouser.com/ds/2/389/esm3030dv-954688.pdfhttps://www.mouser.com/ProductDetail/STMicroelectronics/ESM3030DV?qs=%2fha2pyFaduiVw8R86C0rzL9R%2fJHzywOFQfAGTeyHdMw%3d30$ zero in stockThey are in end of life warningYou have this one, 36 parts left, and the price is +/- 60$https://www.mouser.com/ProductDetail/STMicroelectronics/ESM6045DV?qs=sGAEpiMZZMshyDBzk1%2fWixbhOhHbn%2fdrv65Jk3f%252bGm0%3dIf you search this : NPN DARLINGTON POWER MODULEGoogle fuu wil show you some results, you have some modules on ebay ... its the datasheet who's hard to get ?good luck
Heathkit Nixie DMM behavior - Page 1
Forum section: electronics / repair

author: rea5245
author_rank: Frequent Contributor
timestamp: October 29, 2018, 04:35:23 pm
content: Hi,I picked up a Heathkit IM-1202 digital multimeter with nixie tube display cheap at a flea market. It appears to work: the display turns on and it gives approximately accurate readings for resistors and AA batteries.I needed to troubleshoot an old Heathkit IO-21 oscilloscope so I figured what better way to do it than with my Heathkit nixie DMM? But when I connect the negative terminal of the DMM to a ground point in the 'scope and turn the DMM on, the DMM display stays dark. If I disconnect the ground, I see small sparks.The 'scope is turned off and unplugged so this can't be a ground loop. The positive terminal of the DMM is not connected to anything yet, so there's no circuit between the scope and the DMM. Even if there are charged caps in the 'scope, the fact that there's only one wire between the 'scope and the DMM should mean there's no problem. Shouldn't it?Any idea what's going on?Thanks,Bob

author: floobydust
author_rank: Super Contributor
timestamp: October 29, 2018, 04:50:28 pm
content: The Heathkit IM-1202 has an earth-grounded chassis/floating inputs but there might be a path for a DC rail or something internally to be (accidentally) touching the chassis ground.I would say you have an oddball ground fault inside the DMM.Check continuity between the multimeter's chassis GND, power cord GND and (-) input jack, I think with polarity switch "-".Check C118 on power transformer secondary BLK wire 0.01uF 1kV.The scope is probably still grounded, even though unplugged its case can touch other equipment or a metal workbench.

author: rea5245
author_rank: Frequent Contributor
timestamp: October 29, 2018, 04:53:53 pm
content: Thank you. The scope and the prongs of the power cord are resting on an anti-static mat, which in turn is on a wooden table.I'll look into your other points.

author: floobydust
author_rank: Super Contributor
timestamp: October 29, 2018, 07:59:33 pm
content: A bench anti-static mat can also be a part of a ground fault. Some anti-static mats are low resistance (100's ohms) - always good to know your mat, by taking an ohmeter to it. Some people use them upside down, where the highly conductive layer is not on the bottom-side but instead on the top-side.Usually a mat is grounded through a 1MEG resistor, but some people wire it direct to powerline (earth) ground.Placing metal equipment on top of the mat can also give it a low resistance path to earth ground, or between equipment enclosures. Think of having a bare metal benchtop, anything touching it can ground it.But the first link is the multimeter is not floating, so I would also chase that down.
Tefal induction cooktop working but not heating ;-) - Page 1
Forum section: electronics / repair

author: pagaille
author_rank: Newbie
timestamp: October 28, 2018, 09:41:45 am
content: Hi,Any pointer to help me repair my portable induction cooktop ? (TEFAL IR-2018)Symptoms : suddenly cease to heat. No error message. When changing program / power level, the display flips between the previous program and the animation showing that the plate is supposed to heat.So far I tested the usual suspects :- Power supply- IGBT --> not shorted (no functional test done though)- Diode bridge- Safety Relay- Capacitors- Some low power components around the IGBT driving stage.- Thermistors (3 on the plate, one under the IGBT) looks ok.Everything is ok. The device looks ok and is well engineered (european standards).When powering on there is +320V. If I start to cook the voltage at the coil falls to zero (to be confirmed, I should measure again) and nothing else happens.Without schematic it's hard for me to get other ideas. Any advice ?Thanks :-)Matthieu

author: abraxa
author_rank: Frequent Contributor
timestamp: October 28, 2018, 04:50:59 pm
content: If there's no error message then either it lacks circuitry to measure something essential or something is broken that can't be measured. I'd be surprised if they measure the voltate across and the current flowing through the coil, so from my limited experience with power electronics, I'd guess that either the IGBT isn't conducting as well (anymore) as it should or the connection to the coil is broken. What's the resistance of the coil anyway? Maybe one of the connectors suffered from stress? Maybe one of the coil connections broke from vibration of the coil itself?
[solved] smd component identification CCA48 - Page 1
Forum section: electronics / repair

author: mnt22
author_rank: Contributor
timestamp: October 29, 2018, 02:09:30 pm
content: I need help with this device goes by "CCA48"Thanks for everyone

author: ElecSeb
author_rank: Regular Contributor
timestamp: October 29, 2018, 05:36:17 pm
content: Torex - XC9235B08C4R-Ghttps://www.torexsemi.com/file/xc9235/XC9235-XC9236-XC9237.pdfDo not always look at the last digits, these are 9 out of 10 times part of date code.so when looking on CCA25, go like this:CCA25CCA2CCAAnd when you find a datasheet go through it to check if the marking is corresponding your CCA25 (date mark is 9 out of 10 times names in the datahseet)

author: mnt22
author_rank: Contributor
timestamp: October 29, 2018, 07:23:39 pm
content: Quote from: ElecSeb on October 29, 2018, 05:36:17 pmThank you very much ElecSeb
How to ID contact pads under rotary knob Fluke 17b - Page 1
Forum section: electronics / repair

author: billbyrd1945
author_rank: Regular Contributor
timestamp: October 26, 2018, 08:24:42 pm
content: I'm doing some trouble shooting on my Fluke 17b. I can't find a diagram for the contacts and was wondering if any one out there has a general knowledge of how these things are laid out. I realize that every single meter in the world may be different. But, maybe there's some universal practice for meter voltage and ground (for example). Right now I get no display whatsoever. I figure two of the rings would account for that. Any help will be appreciated.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 26, 2018, 10:10:08 pm
content: They can be anything the company want it to beyou can trace ground pads with another meter.Normally you super impose the dial contacts pins on them to have some clues what are the selected functions vs the selected traces padsBut if your display is blank or no power, maybe the two inner rings of pads must be power on/off related ? they are the longest ones ? check if they go the the pattery pads / connector / contactsTeardown EEvblog #344Has it been dismantled on the lcd section / window, are the zebra contacts okay ?

author: billbyrd1945
author_rank: Regular Contributor
timestamp: October 27, 2018, 01:29:47 pm
content: Thanks for the suggestions. But it's academic now. My Fluke is now a for-parts-only meter. In an attempt to increase the pressure on the springs, I broke two of them. Any body got any of those springs? I'm talking about the ones under the knob that come in contact with the copper tracings.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 27, 2018, 04:44:44 pm
content: Any idea what happened to the meter before you took it apart?

author: billbyrd1945
author_rank: Regular Contributor
timestamp: October 28, 2018, 12:16:55 am
content: "Any idea what happened to the meter before you took it apart?"Yes. It all started a couple of months ago when I discovered a broken battery prong (corrosion). Had never been under the hood and had no desire to poke around. I was forced to fabricate a battery prong. After that, I had some problems related to improper reassembly and resistance from solder flux. With help from the forum got it up and running and thought I was done. Then, I noticed that I had about ten ohms extra resistance so that a 10R would show 20R. Tried trimming with no success. Decided that the selector pad needed even more cleaning and set out to do that. And since I was there.... why not put some additional bend on the leaf springs: more contact pressure to the tracings. Bad mistake. Broke two of them. I've reached out for any salvage parts that anyone might have, but don't expect to get any. I loved that meter-- as close as I'll probably ever get to having a real Fluke. But, alas, it's toast.
Looking for parts for Fluke 17b - Page 1
Forum section: electronics / repair

author: billbyrd1945
author_rank: Regular Contributor
timestamp: October 27, 2018, 02:57:38 pm
content: Looking for a set of metal leaf springs that go under the selector knob. Do any of you have some of these springs, or know a source for getting them?Thanks.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 27, 2018, 04:04:34 pm
content: Ask Fluke USA directly, for many meters they are no substitutes for them ... tried to have them to rebuild an 189 with no luck from Fluke, had to buy used/defective meters
Water ingress into an electronic wrist watch - temporarily put in freezer? - Page 1
Forum section: electronics / repair

author: e100
author_rank: Frequent Contributor
timestamp: October 27, 2018, 09:49:25 am
content: It's going to take a week for the special tri-lobe screwdriver to arrive so I can take the back off and attempt to dry it out.While I'm waiting, is it a good/bad idea to store it in freezing conditions so as to reduce the corrosion rate, or will the ice crystals do more damage as they expand while freezing?

author: Rerouter
author_rank: Super Contributor
timestamp: October 27, 2018, 10:04:24 am
content: put it in a box with some proper desiccant packets (Not rice!) and leave it on something that runs hot, e.g. a settop box,Or even better go to a watchmaker, ask them to swap the battery for you and to not put the back cover on, will probably cost $20 for a battery swap,

author: Ian.M
author_rank: Super Contributor
timestamp: October 27, 2018, 11:17:36 am
content: Its important to immediately remove the battery so the circuit has no power (to stop electrolytic corrosion) and get its interior as dry as possible as soon as possible to minimise damage. Although freezing it to -20 deg C would slow down corrosion, you risk it destroying the LCD, and popping off or cracking any components on its PCB that have a lot of water trapped under them.As Rerouter said, go to a jewellers that does watch batteries as soon as possible, preferably as soon as you read this, ask them to open it, remove the battery, and give it back to you with the case open. However *DON'T* have them put the new battery in!If the water was salty or heavily contaminated, odds are its going to need manufacturer's service or be BER. The longer you wait to get it dried out and the saltier the water, the lower your odds of success.
Restoration of old Sony ICF 6700W receiver - Page 1
Forum section: electronics / repair

author: KarlLightner
author_rank: Newbie
timestamp: October 26, 2018, 07:24:27 pm
content: Hello, Im a 79 year old retired Ham radio amateur. (N3CWH), I am restoring an old Somy ICF6700W receiver. I'm a little shaky and my eyesight isn't so hot. The S meter is sticking badly. m I tried a number of things to no avail. Is there anyone who can repair this meter for me. I'm willing to pay.Contact me at karl.lightner@gmail.com
SONY KDL32S5600 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: October 29, 2018, 06:45:12 pm
content: Good evening everyone!! I have a TV SONY KDL32S5600 which has the following symptom: when the ignition is green, then abruptly the relay RL101 switches and the LED flashes 3 times. I changed the NAND on the main board (IC4701) by a programmed delivered NAND. Problem: the fault remains unchanged. I went through several forums and it seems that the fault is in the power (power protect). By watching more closely I realized that C216 remains charged more than 300V and unplugging the tv the light continues to flash a long time which seems to be a power failure that does not consume power to discharge the capacitor filtering. Has anyone had this failure ?? If so, what are the components involvedThanks for your help!

author: lionelkjh
author_rank: Frequent Contributor
timestamp: October 31, 2018, 07:59:21 am
content: help!

author: t1d
author_rank: Super Contributor
timestamp: October 31, 2018, 09:20:05 am
content: Warning. TV circuits can hold dangerous power levels. Take all precautions, to prevent electrocution. Discharge caps, etc.If you suspect that there may be an issue with the power protection, I suggest that you check for a bad diode. A bad diode or e-cap is very typical. Bad e-caps can, often, be found with a close visual inspection. Look for leaks and/or swelling.I imagine the flash code means something in particular, but you will likely have to dig for that, yourself. A cap can power an LED for a good long while, depending on what components are involved.Here is the manufacturer's document site. The bigger operations manual has a troubleshooting section that mentions blink codes. But, I didn't see your pattern.https://www.sony.co.uk/electronics/support/televisions-projectors-lcd-tvs/kdl-32s5600#downloadsYou may get better information, on a TV repair forum. They're out there. Be careful though, some are pay to play.Also, I think YouTube has some channels where you can ask questions. I did a quick YT search for your make and model and found several videos directly related to your issue.https://www.youtube.com/results?search_query=SONY+KDL32S5600The reason you did not get a quick response is likely the fact that most folks on this forum think you have a basic responsibility to investigate these types of resources yourself. I, on the other hand, think that, sometimes, folks don't know about these basic resources. Hence, why I replied.Keep at it. Ask more questions, if necessary.
34970A calibration data readout? - Page 1
Forum section: electronics / repair

author: H.O
author_rank: Frequent Contributor
timestamp: October 26, 2018, 01:52:31 pm
content: Hi,I've recently aquired an Agilent branded 34970A, complete with printed manual, service guide and schematics for $250+S/H and apart from a dead 3V lithium battery and a noisy fan it seem to function, at least on DCV and OHMs. SCPI over RS232 works and after warming up for an hour it agrees fairly well with my Rigol DM3068:Now, I've obviously read about the problem with the FRAM-chips in these units and I'm about to order a couple from Digikey. I have a TL866 programmer which is supposed to read/write the FM24C04 but I'm a bit reluctant to mess around with this machine just for the sake of it since it seems to work just fine. If it ain't broke and all that.So I'm asking if anyone knows of a way to do a closed case "dump", or backup if you will, of the calibration data which can then later on be used to restore the calibration in case the FRAM dies?
Good set of opening / pry tools  - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: October 25, 2018, 08:41:46 pm
content: For opening general electronics (not just cellphones or something) can anyone recommend an ebay kit or some other place that won't charge hyper inflated prices for a few pieces of plastic and metal ?I don't want some random ebay junk that breaks after a couple of uses tho either

author: Mr. Scram
author_rank: Super Contributor
timestamp: October 25, 2018, 08:51:23 pm
content: Quote from: lordvader88 on October 25, 2018, 08:41:46 pmI've said this in another thread and I'll say it here. You want spudgers that aren't too sturdy. The idea is that you'll damage or break your spudger before damaging or breaking your project.

author: jpanhalt
author_rank: Super Contributor
timestamp: October 25, 2018, 08:55:00 pm
content: Try plastic razor blades available at boat stores (and on the Internet) for scrapping stuff off fiberglass boats and other non-scratch uses.

author: ataradov
author_rank: Super Contributor
timestamp: October 25, 2018, 08:57:28 pm
content: Absolutely the best thing I bought for prying are guitar picks. Like this sethttps://www.ebay.com/itm/Guitar-100Pc-Acoustic-Electric-Guitar-Pick-Plectrum-Mixed-Assorted-Colors-W-Box/112451055976They are cheap, available in variety of thicknesses, and shaped perfectly for prying. And they have never damaged the plastic. They would mangle themselves first, but it is not important.

author: lordvader88
author_rank: Frequent Contributor
timestamp: October 25, 2018, 09:00:10 pm
content: Good point Mr.Scram. Pretty much any plastic cases I've opened, with improper tools, I've always left marks, or broke stuff

author: metrologist
author_rank: Super Contributor
timestamp: October 25, 2018, 09:37:48 pm
content: I've cut up plastic containers, but I think I will check out guitar picks

author: eb4eqa
author_rank: Regular Contributor
timestamp: October 25, 2018, 10:24:07 pm
content: +1 for the guitar picks, absolutely. Just make sure you use use one that matches the color of the device you are opening. Otherwise it wont work that well.Roberto

author: ataradov
author_rank: Super Contributor
timestamp: October 25, 2018, 10:39:23 pm
content: I never had any problems with colors. They don't mar at all. At least one the types of plastics commonly used for electronics enclosures.

author: cs.dk
author_rank: Unknown
timestamp: October 26, 2018, 03:59:46 am
content: I've been quite happy with the stainless steel iSesamo tools.https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=iSesamo&_sacat=0
Help with finding unknown driver transistor marked 4948 What is it? - Page 1
Forum section: electronics / repair

author: tru3533
author_rank: Regular Contributor
timestamp: October 25, 2018, 10:22:55 pm
content: Hi,I need help with finding an unknown driver transistor marked 4948 What is it?Any idea?Any help is highly appreciated, thank you.

author: JFJ
author_rank: Regular Contributor
timestamp: October 25, 2018, 11:11:40 pm
content: It might be a Vishay dual MOSFET:https://www.vishay.com/docs/72847/si4948be.pdfThe part markings are explained here:https://www.vishay.com/docs/72762/72762.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 25, 2018, 11:14:16 pm
content: Traces look like dual MOSFET.Si4948 sounds like a winner.Soldering on that connector is sketchy as hell...Tim

author: tru3533
author_rank: Regular Contributor
timestamp: October 25, 2018, 11:40:41 pm
content: WhowJFJ that was quickFor sure a winner. Thank you so much.TimLuckily I had another board to compare, the FET was blown off the pcb.PS soldering not by me :-)
Iwatsu ss-5212 oscilloscope schematic / service manual - Page 1
Forum section: electronics / repair

author: adam_ant
author_rank: Newbie
timestamp: October 25, 2018, 06:22:49 pm
content: Hi guys,I recently acquired an old Iwatsu ss-5212 oscilloscope that requires some repair (looks like a horizontal deflection issue). Problem is the scope didn't come with the manual and the service data appears to be unavailable (even from Iwatsu themselves) I was wondering if anyone has the schematic for this scope?Any help would be greatly appreciated!
TEAC T-H300DABmkII, unusual failure mode - Page 1
Forum section: electronics / repair

author: Specmaster
author_rank: Super Contributor
timestamp: October 25, 2018, 11:39:36 am
content: I have this TEAC Tuner that I purchased of Ebay as faulty, cannot bring it out of standby mode, done all the usual things so far, checking power supply etc. and everything appears to be OK so after much head scratching I thought lets check the switches on the front panel, of which there 11 of them, and I discovered that every single one of them was open circuit and thats something that I have never come across before. Has anyone else experienced this before?I'm just in the process of ordering some more.

author: mzacharias
author_rank: Frequent Contributor
timestamp: October 25, 2018, 01:59:07 pm
content: Worked on consumer audio gear - mostly Pacific Rim, until 2016. Tact switches are a very common problem, especially where cigarette smoke is involved.One can check the size and footprint, and order them 100 at a time from eBay for under 5.00 U.S. - had very good luck with that.

author: cvanc
author_rank: Frequent Contributor
timestamp: October 25, 2018, 02:26:49 pm
content: Yes, this is a common problem. Many of these tactile switches are quite low quality and do not last long in the wild. Try to find actual Omron brand replacements if possible (of course the risk of fakes is high, sadly).Good luck with your fix.

author: Specmaster
author_rank: Super Contributor
timestamp: October 25, 2018, 05:46:16 pm
content: All fixed and working again, it was those pesky tactile switches So now I'm on the lookout for a replacement DAB module to fit the tuner. The reason for this is that I sourced the dead tuner as a donor of a DAB module for a TEAC CR-H240 receiver, which was removed and fitted and so the CR-H240 is now fully working again. Then I decided to have a go at the tuner and now that its working OK on FM and AM, I need to resolve the DAB as well so what started out as a donor is a semi working unit and with a new DAB unit will be one more in the pile of repaired gear that keeps growing, I need a bigger house
can i recover this battery pins ? - Page 1
Forum section: electronics / repair

author: ammjy
author_rank: Regular Contributor
timestamp: October 31, 2018, 01:06:44 pm
content: Hello !! Thanks you always for kind help !i have a question about battery pin (please see the photo attached)cause of not correct size battery. pins now unbalance.how can i recover this without change component or teardown ??please give to me advise !

author: PKTKS
author_rank: Super Contributor
timestamp: October 31, 2018, 01:29:02 pm
content: You should replace the pin...otherwise you must fill the space between the minor oneI would try a solder drop on the the battery side ..small drop or solder blob to fill the space...long shot...

author: ammjy
author_rank: Regular Contributor
timestamp: October 31, 2018, 01:32:10 pm
content: Thanks you for kind reply, PKTKS.i have another question.if, no problem to use - i don't need replace right ?

author: brabus
author_rank: Frequent Contributor
timestamp: October 31, 2018, 04:01:46 pm
content: The pins seem fine, I would not touch them.If the correct battery works, I would do nothing at all.If you touch them, you risk breaking them; changing the entire connector will be then difficult.
small foam tape - Page 1
Forum section: electronics / repair

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 24, 2018, 08:23:47 pm
content: I need a small roll of foam tape which is about 1/8" wide by 1/8" thick to replace a some short strips that are used to press hold flexible conductors to a pcb. My search of places like digikey and mouser didn't find anything that small. Anyone suggest a source?Thanks

author: tkamiya
author_rank: Super Contributor
timestamp: October 24, 2018, 11:03:27 pm
content: Hobby shop or craft shop?

author: sleemanj
author_rank: Super Contributor
timestamp: October 24, 2018, 11:13:20 pm
content: Aliexpress1/8 is close enough to 3mm, search for foam tape 3mm thick, you might not find 3mm wide 3mm thick, but I'm sure you could manage cutting a wider tape to size.
sencore sc61 - Page 1
Forum section: electronics / repair

author: pete g
author_rank: Regular Contributor
timestamp: October 22, 2018, 01:21:30 am
content: hi all, I have a sencore scope that has started acting up. when I hook up a probe to either chanel a or b I get a 160mvpp signal at 2.4khz. have tried different probes, even just a straight wire, with the same results.this occurs with no connection to anything. can someone help. have checked filters in power supply. are o.k. I have another scope to use for troubleshooting. it seems like the probe wire is acting like an antenna. help plz.

author: mzacharias
author_rank: Frequent Contributor
timestamp: October 24, 2018, 10:52:07 am
content: Does it behave this way using a probe (direct or x10) on a circuit under test? Or connecting to the probe compensation tab on the front?Open probes ARE like an antenna - they pick up all sorts of crap.

author: pete g
author_rank: Regular Contributor
timestamp: October 24, 2018, 05:01:42 pm
content: hi, and thanks for replying. I think I fixed it. I changed every electrolytic I could see. it seems to be working. I really like this scope, and hope its fixed.

author: mzacharias
author_rank: Frequent Contributor
timestamp: October 24, 2018, 05:50:58 pm
content: Glad that worked out for you. I grind my teeth when I hear "re-capping" so damn much, but sometimes it does work.

author: pete g
author_rank: Regular Contributor
timestamp: October 24, 2018, 06:04:33 pm
content: yes, well I figured on a 30 year old scope, it probably was the thing to do. time will tell. thanks.
Bypass digital audio processor on a Lg Ht33s - Page 1
Forum section: electronics / repair

author: debi
author_rank: Contributor
timestamp: October 24, 2018, 02:22:50 pm
content: Hi guys,i m facing an electronic problem and my knowledge are far from being professionnal level. First of all im french sorry for my english. I started using a home cinema from LG HT33s which was left in a wardrobe fro years. It has few options but the only one who interests me is the Audio Aux IN because i would like to use it with my 4K TV and the speakers on this tv are not good.At the beggining it worked really well for few weeks. The problem is i always left the head unit turned on (might be the cause of the failure). So one day, the TV was turned off and i heard like an explosion from the speakers of the LG HT33S, the LG turned off by himself... i directly turned on the tv and on turn on the LG. The LG could turn on but was not responding to the remote control and few seconds after the LG turns down again by himself.. It s not possible anymore to use the Aux IN option. I don't know if the head unit is faulty, there was no burn smell.To fix this, i would like to bypass the head unit and all the amplifier PCBs and audio IN/out are on the back of the subwoofer. The problem is i don't know if it's possible as everything might be controlled by a processor inside the head unit... It's really frustrating because the LG speakers and the subwoofer are good. In the same time, i really enjoy repairing basic electronic stuff, using my welder etc but i would like someone to tell me if it's totally time waisting to think it s possible to bypass the head unit and be able to use the original LG amplification without controlling the stuff with a remot control. I understand a new amplifier would solve the problem but i would like to not spend money as the original amplifier is located behind the Subwoofer.i decided to open the rear of the subwoofer and by following the RCA audio IN on the pcb, i can read on a socket FL and FR which is obviously Front Left Front Right. these cables are going to the second PCB where a PULSUS digital audio processor is located... if im right by controlling the head unit with the remote control, the head unit send messages into the cable link to the digital audio processor located in the sub and the pulsus select the option (cd, DVD, Ipod, Aux in, ...) ??I attached the photos to give you an idea.
Fluke 287 problem - Page 1
Forum section: electronics / repair

author: Nevi44
author_rank: Newbie
timestamp: October 23, 2018, 08:32:30 pm
content: Evening all.I have a problem with VDC on my Fluke 287. When measuring 12V DC supply VDC keeps dropping until it stabilizes around 10.85V. After reading many topics on this forum, I am wondering if this can be an issue with MOV’s? They all look intact but two of them (RV2 and RV3) are measuring OL and RV1 19.85 MΩ resistance. Is this correct?

author: retiredcaps
author_rank: Super Contributor
timestamp: October 24, 2018, 08:06:19 am
content: Quote from: Nevi44 on October 23, 2018, 08:32:30 pmNo. All should measure 0L. Desolder RV1, RV2 and RV3 and retest to see if meter works. Measure RV1, RV2 and RV3 out of circuit to verify readings.If RV3 still reads 19.85M ohm, replace. You might also consider replacing RV2 and RV3 as these MOVs are about $1.50 USD each.

author: nixxon
author_rank: Frequent Contributor
timestamp: October 24, 2018, 10:43:53 am
content: Quote from: retiredcaps on October 24, 2018, 08:06:19 amTo verify if there is a MOV-related problem, would it be sufficient to remove RV1 only. Only RV1 is connected to COM if I have measured correctly...
Help to repair Fluke 1587 insulation tester. - Page 1
Forum section: electronics / repair

author: lsizquierdo
author_rank: Newbie
timestamp: October 23, 2018, 05:28:27 pm
content: Hi. I have a Fluke 1587 insulation tester, now on any scale reads 0 volts or 0 ohms or beeps like if you shorted all functions are working but measuring 0 on all types. Any suggestions?? I can post pictures of the pcb. I tested with another multimeter looking for a short circuict the terminals with no luck.

author: lsizquierdo
author_rank: Newbie
timestamp: October 23, 2018, 08:54:09 pm
content: Trying to find the problem, I removed the IC TL 24351 and the problem seems to be gone. There is no measurement, only ---- as normal.