hybridfree/eevblog-posts huggingface dataset:
HP E3631A another one comes to life - Page 1
Forum section: electronics / repair

author: Rick
author_rank: Frequent Contributor
timestamp: August 23, 2014, 07:18:47 pm
content: I almost finished repairing one of those. Only the "unreg" issue mentionned remains and the optoisolators are ordered.Big thanks to free_electron who explained it all and all I had to do was to follow the explanations and the advices.Great forum!

author: idpromnut
author_rank: Unknown
timestamp: August 24, 2014, 11:27:24 am
content: One of the Agilent supplies that I repaired recently had one (or more) of the output pass Fets blown and the UNREG annunciator was lit. But in that case there was no output on the faulty channel.

author: idpromnut
author_rank: Unknown
timestamp: August 25, 2014, 12:37:07 pm
content: Hmm, I'm not sure what to expect in that case. I ail try to have a glance at the schematics for this supply at lunch.
samsung 920n monitor video problem - Page 1
Forum section: electronics / repair

author: stoica adrian
author_rank: Contributor
timestamp: July 13, 2014, 11:29:16 am
content: Hi, can someone help me with this defect.So far i do this1 Check the routes, seams, connections jacks, solder ok2 Check the components, especially capacitors with ESR meter ok3 Check the power supply okIt seems that the problem is in the video or display , has anyone an idea?

author: simplifyiyuk
author_rank: Contributor
timestamp: July 13, 2014, 02:44:47 pm
content: check the driver board on the LCD panel itself (one under the don't touch very delicate or similar warning),but be careful. might be that a component (or multiple) is shorting onto the metal surround. had a similar issue with a AUO and some other cheaper panels where the capacitors where shorting to the casing (might be able to hear a buzz or clicking). just an idea from experience.

author: hobo2566
author_rank: Contributor
timestamp: July 28, 2014, 09:37:57 pm
content: Probably problem on logic/driver board, check caps there, possibly change them. Or just try with different screen panel.

author: paulhm81
author_rank: Regular Contributor
timestamp: July 29, 2014, 02:10:18 pm
content: I had a screen with the same issue. I'm sure it's the display because I tried with another one and it worked fine. It could also be the ribbon going tot the screen. I didn't find any obvious faults on the screen pcb and it wasn't worth the time because the usual suspects are the chips on the flex cables and the connections with the glass.

author: ijchan223
author_rank: Contributor
timestamp: August 24, 2014, 08:11:13 pm
content: to me it looks like a bad panel, i would open the screen till you can play with the tabs and see if it changes.
Hitachi Mainboard Replacement -- numbers not exactly the same - Page 1
Forum section: electronics / repair

author: mathsquid
author_rank: Frequent Contributor
timestamp: August 14, 2014, 08:03:46 pm
content: I'm trying to repair a Hitachi LCD television. It's an ultravision, model number L42S504. I followed the troubleshooting procedure in the service manual, and it says to replace the mainboard. I made some attempts to repair the mainboard, but was unsuccessful.The power supply board seems to work fine, and if I use a jumper to put 5v to the PS_ON pin, the backlight turns on and I can get 12v and 24v from the power supply.So I decide to replace the mainboard, which has model number 715G3269-M01-003-005K. Here are two pics of the dead board in my TV.When I look up this number on ebay, I no matches. However, if I just search for 715G3269, I get several matches like that look like the right board, but the number on them is 715G3269-1. For example,http://www.ebay.com/itm/INSIGNIA-or-HITACHI-MAIN-BOARD-715G3269-1-/301275415503?pt=US_TV_Boards_Parts_Components&hash=item46256a03cfI don't know much about board naming conventions--I don't know if this board on ebay, the 715G3269-1, is a new revision that will work fine or if it won't work. Do you guys have any advice?Thanks.M.S.

author: KJDS
author_rank: Super Contributor
timestamp: August 14, 2014, 08:54:21 pm
content: At that price I'd take the gamble. What can possibly go wrong?

author: Monkeh
author_rank: Super Contributor
timestamp: August 14, 2014, 09:11:25 pm
content: Quote from: KJDS on August 14, 2014, 08:54:21 pm

author: wraper
author_rank: Unknown
timestamp: August 14, 2014, 09:49:00 pm
content: Sameboard, maybe minor differences like languages, revision, mfg site. Likely TV will become a different model with some features enabled/disabled. That part number actually is used in many models. Would be useful to find how to enter service menu to change settings to the right/similar model.Edit:Actually I can see differences in voltage regulators, but IMO should be compatible.

author: ijchan223
author_rank: Contributor
timestamp: August 24, 2014, 08:05:16 pm
content: typically if the connectors are the same it will be a direct drop in.
Zoll 1600 Defibrillator Repair - Page 1
Forum section: electronics / repair

author: vargasmir01
author_rank: Newbie
timestamp: August 24, 2014, 05:06:07 pm
content: Hello, this is my first message on the eevblog forum but I've been a long time viewer of the youtube channel and now that i'm on a bit of a trouble this is the first place that came to my mind(Also sorry for any mistakes I'll try to make as few as possible)The problem began when we started testing a defibrillator that was in our university and was supposedly not working. Repairing and restoring this defibrillator is the main project in one of the classes I'm taking right now, and at first, the defib worked great without any noticeable problems.We got the service manual and we started the test routines the manual stated... Then something blew up inside, the defib jumped half an inch and stopped working.No exterrnal damage could be seen altough a strong burnt smell appeared on the area, upon taking it apart we found that two fuses had blown up and a transistor (BSS295) had exploded also.And the problem is that I can't seem to find a place where to buy this transistor or how to make a replacement board to make the defib work again, also I don't have lot of experience working with n channel transistors.Help? Please

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 24, 2014, 05:32:40 pm
content: Your thumbnail photos are too small and out of focus for us to see anything useful.And Imageshack seems unwilling to offer the full-size images even for download.Making people download images (vs. simply linking to them) is rather hostile and will turn-off many people who might be able to help you.Imageshack isn't doing you any favors here.We are assuming you don't have a schematic diagram (which puts you at a significant disadvantage).We are also assuming that you are doing this only as a laboratory exercise and do not intend to put the unit back into life-saving service.Have you attempted to find a substitute for the transistor?Please complete your profile to at least disclose what country you are in.

author: kolbep
author_rank: Frequent Contributor
timestamp: August 24, 2014, 05:37:42 pm
content: I would hate to be the test subject when you get it working again

author: vargasmir01
author_rank: Newbie
timestamp: August 24, 2014, 06:31:53 pm
content: Ok, I've changed the images, sorry for that :S it's the my first interaction with forums in a long time and back in the day imageshack was the way to go xD now it's all crappy and stuff.And to answer your question, no it is not supposed to go into hospital service again, we have a defibrillator tester that will measure the output once we get it running again. On that basis, we need to get it working and it needs to be able to deliver the 90% of the shock capacity selected by the user.And thanks for the advice
Re-Capping Old Motherboard. - Page 1
Forum section: electronics / repair

author: AnnabellaRenee87
author_rank: Contributor
timestamp: August 15, 2014, 02:58:36 pm
content: Hey Everyone,I am going to be re-capping a old PC Motherboard and want to know if I should go for low or high ESR Caps.I seem to be finding conflicting information around the interwebs, anyways, thanks for any information you all can provide

author: bobcat
author_rank: Regular Contributor
timestamp: August 15, 2014, 06:25:12 pm
content: Linear and some switching regulators can be fussy about capacitor ESR as well as surge spec. Check the data sheets on caps near the regulators. For general power distribution caps, low ESR is the way to go.

author: David Hess
author_rank: Super Contributor
timestamp: August 15, 2014, 10:26:58 pm
content: If this is a common design using a point of load switching regulator with aluminum electrolytic capacitors, then you want low impedance/ESR ones.More recent motherboards use aluminum polymer (solid) electrolytic capacitors which are completely different and should not need replacing.

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: August 24, 2014, 03:14:03 pm
content: Quote from: Neoistheone2000 on August 16, 2014, 12:58:36 AM>QuoteWell,I have no idea where you got this from .Can you please point to a place that actually says High ESR .In my 25 years experience as a computer repairtech i have never seen anything thats not Low ESR in Computer motherboards

author: wraper
author_rank: Unknown
timestamp: August 24, 2014, 03:35:27 pm
content: Non low ESR capacitors are used only in places where no high ripple is present. For example around audio codec IC. All capacitors that have capacitance higher than 47-100 uF always will be low ESR. But you approach this problem in the wrong way. Low ESR capacitors don't come in one grade. First of all you need to find a datasheets for the capacitors you want to exchange. Then choose replacements with same or higher ripple current and same or lower ESR ratings.

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: August 24, 2014, 03:44:38 pm
content: Quote from: wraper onTodayat 01:35:27 AM>QuoteWell,But obviously , And Those never fail ,Only the once that are mostly in the other stages do .These days most repair techs in india have no clue what is esr .They just get a cap and boom boom .But i would say a good branded low ESR cap is really good for reliable working of this .I would like the give you a example .I use 2 chinese P4 boards for some special application .Time and again they were failing so i got real nice low esr caps and recapped them all .Till date never had a issue
HP E3615A DC Power supply 0 to 20 V, 3 A - Page 1
Forum section: electronics / repair

author: arunsjoshi
author_rank: Newbie
timestamp: August 23, 2014, 10:02:15 am
content: I am looking for the schematic of the Hewlett Packard HP E3615A DC Power supply which gives an output of 0 to 20V at a max current of 5 A. Can anyone help by providing the Instruction and/or service manual as the product is now obsolete. I bought it about 20 years ago and it developed a fault only last week. Unfortunately I misplaced the schematic= arunsjoshi@yahoo.com

author: tautech
author_rank: Super Contributor
timestamp: August 24, 2014, 09:08:42 am
content: You can read it online or download after registering:http://ebookbrowsee.net/hp-e3614a-3615a-3616a-3617a-60w-power-supply-manual-pdf-d27108352
Philips / Fluke PM6303 LCR meter service manual required - Page 1
Forum section: electronics / repair

author: Shock
author_rank: Super Contributor
timestamp: August 19, 2014, 03:24:30 am
content: Does anyone have a copy of the Philips / Fluke PM6303 LCR meter service manual?I only have the operating manual.No longer require them.

author: tautech
author_rank: Super Contributor
timestamp: August 19, 2014, 11:16:35 am
content: Quote from: Shock on August 19, 2014, 03:24:30 amhttp://elektrotanya.com/philips_pm6303_lcr_meter_op_1990_sm.pdf/download.html

author: Shock
author_rank: Super Contributor
timestamp: August 20, 2014, 04:08:32 am
content: Says operating manual on the preview.I'm after the service manual.

author: tautech
author_rank: Super Contributor
timestamp: August 20, 2014, 07:53:55 am
content: Quote from: Shock on August 20, 2014, 04:08:32 amSorry, try this one:http://www.apite.com/apitewww/modelo.php?modelosin=PM63010302&marca=260

author: Shock
author_rank: Super Contributor
timestamp: August 20, 2014, 03:16:40 pm
content: The document you have requested is not included in the group of free technical manuals. To download the selected document, you must register on link "INFORMATION & REGISTER"Glad I used a disposable email for that.Many of the sites also have the wrong meter service manual as the PM6303 also.

author: tautech
author_rank: Super Contributor
timestamp: August 21, 2014, 09:04:02 am
content: Spent a bit of time trying to find it for you....not much luck.3 more links:http://chomikuj.pl/martiner/Service+manuals+-+audio/Philips/PHILIPS_PM6301_PM6302_PM6303_service_manual,2493751688.PDFhttp://www.vintage-radio.net/forum/showthread.php?t=93693http://www3.imperial.ac.uk/pls/portallive/docs/1/7293204.PDFLast one is for PM6303A circa 1995You have probably seen them alreadyReally annoys one when it is so hard to find.Suggest if found you upload it to:http://www.tlec.se/index.php/homewhere all can find it and not get robbed by the manual thieves.SorryShockI give up.

author: HighVoltage
author_rank: Super Contributor
timestamp: August 21, 2014, 05:29:14 pm
content: I also have a PM6303 LCR Meter and needed a service manual a couple of years ago and could not find it at all.Then I gave up and bought a PM6303A model.Well, finally I tried to look for the problem on the PM6303 and found the fault in the power supply and fixed it.It seems that some of these older service manuals never made it online or someone does not want them to be online anymore.

author: HighVoltage
author_rank: Super Contributor
timestamp: August 22, 2014, 08:48:14 am
content: Here is someone in Germany selling a PM6303 including the Service manual.May be the seller is willing to scan it for you.http://www.ebay.de/itm/Philips-PM6303-RCL-Meter-Messbrucke-RLC-mit-Service-Manual-/331238655615?pt=Mess_Pr%C3%BCftechnik&hash=item4d1f5cc67f

author: Shock
author_rank: Super Contributor
timestamp: August 22, 2014, 04:36:57 pm
content: I'll ask the guys on the vintage radio forum as well. That ebay listing is from a dealer so I don't like my chances there
Packard Bell Monitor repair - Page 1
Forum section: electronics / repair

author: Zongo
author_rank: Newbie
timestamp: August 21, 2014, 08:06:35 pm
content: My monitor suddenly stopped working, but started making a ticking sound which I figured was coming from the internal speakers. So I opened it up and noticed some bad capacitors. I have just replaced the ones that visually looked bad because I don't have access to an ESR meter.The sound from the speakers is now different and louder, and I think I'm picking up some faint ticking from somewhere else too. But no sign of life from the panel.Could it be that there are more bad capacitors in there causing this issue, or is there a deeper problem that is not so easily fixed?I'm asking because low ESR capacitors are hard to get around here. It cost me €5.80 to get just 3, and there's 7 more that could need replacing.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 21, 2014, 08:44:56 pm
content: Ticking suggests the SMPS is trying to start, but can't maybe due to1) bad startup cap (probably 10uF or 22uF). Measure the DC voltage across this capacitor. It should be stable and not fluctuating.2) bad SMPS IC. Find the datasheet and see what the startup voltage should be for VCC. See if VCC is shorted to GND.3) shorted diode. Test diodes to see if they are shorted.
Looking for Datron/Wavetek 1271 or 1281 display unit. - Page 1
Forum section: electronics / repair

author: nadona
author_rank: Regular Contributor
timestamp: August 14, 2014, 07:25:17 pm
content: Hi,I am looking for a Datron/Wavetek 1271 or 1281 display unit - right side.Anybody know who was the vendor and part number?Thank you very much in advance.

author: quarks
author_rank: Frequent Contributor
timestamp: August 15, 2014, 09:02:47 am
content: afaik the V.F. Dot Matrix Display has part# 800028-2 and manufacturer was ITRON

author: nadona
author_rank: Regular Contributor
timestamp: August 15, 2014, 06:27:12 pm
content: Quote from: quarks on August 15, 2014, 09:02:47 amThank you very much.I sent the message to the company. Waiting for good news.

author: pelule
author_rank: Frequent Contributor
timestamp: August 17, 2014, 10:31:16 pm
content: Hi,the right display for my Datron 1281 is damamged during shipment and fully smashed.Thus I am looking for one either.Thas what I found already...Its a DC405E2 from ITRON/Japan. It is 1x40 char, 5x7 DOT matrix, 5mm sized VFD display.I got in contact with the manufactor, the display is not available anymore since several years.ITRON is not able to supply specs for the display or to recommend a replacement.Thus I have started to search for a NOS part or a nearly fitting alternative display.As my display is smashed, I can not measure the size of the display.Can you give me the size of it?Lenght, Width, Thickness of the glass, best would be in mm, as I am in Germany.Does anybody have some more technical details of the display?(voltage, current; pin assignment of the segments/filaments and heating pins)Any help/information is highly appreciated.

author: nadona
author_rank: Regular Contributor
timestamp: August 20, 2014, 09:04:25 am
content: Quote from: pelule on August 17, 2014, 10:31:16 pmFinally I got the reply from ITRON and get the same answer like you.The part that "quarks" gave me is actually "Wavetek RF Product, INC" SKU number and the company is bought by a german company. And they said no stock, too.I contacted Fluke and they couldn't find the stock number in their database.Even if your display was smashed, you can measure the thickness and height accurately, no?

author: pelule
author_rank: Frequent Contributor
timestamp: August 20, 2014, 11:53:13 am
content: I don't have the length of the panel and the pattern (see attached sketch). This I can't measure anymore.But this you need to find an as close as possible matching alternative display.An alternative solution must fit to the housing and also fit to the Daltron "soft key menu" .Would be great, if you could help and fill the missing numbers.By the way, if you look to the history of Datron, there are several companies involded. Now finally it is Fluke. They bought the Daltron Measurment Division from Wavetek.According to Fluke there is no stock of an replacement part.

author: quarks
author_rank: Frequent Contributor
timestamp: August 21, 2014, 09:23:37 am
content: Without taking apart my Wavetek I eyeballed/measured 185mm and 155mm.
acer p193w acting strange - Page 1
Forum section: electronics / repair

author: sevvan
author_rank: Newbie
timestamp: August 20, 2014, 11:00:00 am
content: Hello, first post here, so i have an acer p193 that has a couple of years under its belt but now sudenly its started acting upp, it seems to have trouble starting upp (flickering lines, takes multiple tryes if it even starts) so i teared it open today. It seems to have somekind of white gunk leaking out of the caps on it.So my question is: is it salvagable or should i toss it and just buy a new one?Edit: sorry for the bad quality picture, only had my old camera on hand, will try to get a clearer picture when i get my hands on another cameraEdit2: the cap with the red cross on it is slightly bulky on the top

author: Len
author_rank: Frequent Contributor
timestamp: August 20, 2014, 04:25:48 pm
content: The white gunk isn't a problem. It's silicone adhesive to hold the capacitors in place and keep them from wiggling around.The bulging capacitor is definitely bad. I'd try replacing that to see if it fixes the problem - it does sound like a typical power supply problem to me. Make sure to use a low-ESR cap, if that's what the original one is.
IFR / Aeroflex 2948 (2945A) Firmware...? - Page 1
Forum section: electronics / repair

author: Co6aka
author_rank: Unknown
timestamp: August 16, 2014, 02:39:19 pm
content: Anyone have EPROM dumps of the latest or at least a recent version of its firmware? Anyone know what IS the latest/last version? Thanks!

author: KJDS
author_rank: Super Contributor
timestamp: August 19, 2014, 04:51:10 pm
content: I have an inkling, though it's been 20 years since I did anything with the 2945, that the EPROMs are encoded to each machine. It's probably worth asking on the marconi instruments yahoo group.
HP 3458A Ram test 1 high error. - Page 1
Forum section: electronics / repair

author: johnd01
author_rank: Newbie
timestamp: August 18, 2014, 11:34:37 pm
content: I have a 3458A which starts up with error message"RAM TEST 1 HIGH".I have tried replacing the battery backed up ram on a different unit for the same error. I did not get it to work. Have any of you be able to repair tis problem?

author: Dr. Frank
author_rank: Super Contributor
timestamp: August 19, 2014, 05:43:46 am
content: Quote from: johnd01 on August 18, 2014, 11:34:37 pmPlenty of people replaced the NVRAMs successfully.This error is related to one of the 32kx8 RAMs, and the instrument should continue working after that message, but forget only all settings and programs..The question is, which RAMs you changed on that other unit - the CAL RAM 2kx8 only, or the other two 32kx8 also?Frank
hp monitor 1740 - Page 1
Forum section: electronics / repair

author: kjn4685
author_rank: Regular Contributor
timestamp: July 31, 2014, 10:56:12 pm
content: I have a hp monitor that goes off after a second or two. I've changed all the caps and diodes. Now I am changing the ccfls. I have tested all the voltages and anything that I can test. Does anybody have any ideas.s/n cnc63710j9.

author: hobo2566
author_rank: Contributor
timestamp: August 01, 2014, 11:45:40 pm
content: If your power bard looks like one in attached image, first check if transistors circled in red are OK (5706 or 5707 in most cases), if not check other components circled in green.In most cases flickering on/off is caused by shorted transistor.

author: wraper
author_rank: Unknown
timestamp: August 02, 2014, 12:49:06 am
content: Check secondary windings of the transformer(s), should have something around 1k resistance and less than 5% difference between them.

author: wraper
author_rank: Unknown
timestamp: August 02, 2014, 12:54:55 am
content: If all capacitors are already exchanged and secondary windings are ok, 95% that one ccfl is dead and protection kicks in because of that.

author: Khaveer
author_rank: Contributor
timestamp: August 22, 2014, 09:44:43 am
content: Is it only the backlight that turns itself off? I have a hp l1940t that had the same fault. I couldn't figure out what was causing the problem so I ended up disabling the overload protection hoping that without it the faulty part will simply release the magic smoke but it didn't. I've been using the monitor for a year and it's still ok. If I recall correctly I had to short a cap to disable the protection, so if you won't be able to find the fault I can take my monitor apart and check it.

author: kjn4685
author_rank: Regular Contributor
timestamp: August 22, 2014, 07:37:09 pm
content: I appreciate everybody that contributed to this post. I have it by changing the girls.Again I thank everybody .Lou

author: JoeO
author_rank: Frequent Contributor
timestamp: August 22, 2014, 09:12:38 pm
content: Quote from: kjn4685 on August 22, 2014, 07:37:09 pmWomen were pressing the power off button?

author: kjn4685
author_rank: Regular Contributor
timestamp: August 25, 2014, 06:40:38 pm
content: I did not preview the post before I sent it. Sorry I meant I changed the ccfls not girls.Again I am sorry.I just what to let everybody know that it is fixed.Thank everybody that gave me adviceLou
TTi PL320T-GP Service Manual or How to Remove GPIB board to allow PSU's to run. - Page 1
Forum section: electronics / repair

author: navzptc
author_rank: Contributor
timestamp: August 13, 2014, 04:11:55 pm
content: I have just purchased in very nice condition 2 x PL320 psu's coupled up to a PL320T-GP GPIB unit.I do not require the GPIB unit and planned to remove it and just run the psu's on their own, but on disconnecting the cables from the GPIB unit (and leaving in local mode) I get an error message being shown on both voltage readoutsThere must be a way to run these on their own, and presume it will just be a case of making a few more links on the psu units to work.Any suggestions or relevant service manuals would be most appreciated.Andy

author: macboy
author_rank: Super Contributor
timestamp: August 14, 2014, 03:57:48 pm
content: I know from experience that if you write TTi and ask nicely, they will almost certainly send the user and service manuals to you.
TEX TDS320 cannot power up - Page 1
Forum section: electronics / repair

author: Gibchen
author_rank: Newbie
timestamp: August 14, 2014, 12:43:26 am
content: hi, everybodyMy TDS 320 suddenly shut down yesterday during the test.when I push the on/standby button, nothing happen except the relay is clicking.Dose anybody has the same issue before?or any idea to start troubleshooting?by the way, the fuse is fine.thanks

author: lowimpedance
author_rank: Super Contributor
timestamp: August 14, 2014, 01:49:44 am
content: Not my own experience but I know someone who had a similar issue with their 320, which of course turned out to be the good old electro's in the power supply gone dry.That would be the first thing to do/ check / replace etc.

author: Pat Pending
author_rank: Regular Contributor
timestamp: August 14, 2014, 06:11:35 am
content: Similar problem with a TDS410A due to PSU 110/220 voltage detect failure.In my case a smallish electrolytic was basking in the heat rising from a high wattage resistor directly below it. (PSU is mounted on its side). YMMVThis was located in region of the PSU towards the scope rear.I should have left the leads of the replacement cap long and bent it away from the heat source.
Identify this part for replacement. Fertilizer spreader :) - Page 1
Forum section: electronics / repair

author: mechadrake
author_rank: Newbie
timestamp: August 13, 2014, 03:22:49 pm
content: Hi.This is and adventurous farm fertilizer spreader controller repair question. It stopped functioning properly and found one faulty thing with it. Blown open surface mount part. It looks like an smd diode to me (dimensions approx. 4mm. x 2mm. white strip on one end) but the markings on this say V6 (that is first line) 28 (second line). No manufacturer symbol i could see. Anyone can decipher these markings? I cannot get part like this for replacement now, for it is not a part number for anything it seems.Thank you.

author: rob77
author_rank: Super Contributor
timestamp: August 13, 2014, 04:01:46 pm
content: probably posting a picture would increase your chance to get a helpful answer

author: mechadrake
author_rank: Newbie
timestamp: August 13, 2014, 06:23:50 pm
content: Well maybe it would, but i have written all that is on that thing, my camera took a swim in my tea and not operational and the small parts were always a problem to take a pic. Pretty sure mobile phone camera will do even worse...

author: Legit-Design
author_rank: Frequent Contributor
timestamp: August 13, 2014, 07:13:21 pm
content: Quote from: mechadrake on August 13, 2014, 03:22:49 pmI would guess if it's located between supplies, one pad to ground and another pad for example +5V then it could also be ablack SMD tantalum capacitor. I've seen some that look suspiciously like big smd diodes, but they are just black smd tantalums instead of the normal tantalum colour. To support this assumption tantalums are considered being terribly unreliable, some years back they went up in flames regularly from what I've heard.https://www.google.com/search?q=black+smd+tantalum&tbm=ischsome good reference pictures.

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 13, 2014, 08:20:05 pm
content: Quote from: mechadrake on August 13, 2014, 06:23:50 pmIf YOU can't decipher the printing on the part, we won't have much better luck with only your description.There is a great deal to what it looks like and what the immediate proximity looks like that will give us a clue how to advise you.You may think there is no additional pertinent information, but people who have been doing this for years can read a lot more from a photo than you think.Without a photo, we are only shooting in the dark and unlikely to be able to offer you anything helpful. Sorry.However Legit-Design has a very good point. It could very well be a capacitor. Perhaps 28uF at 6 volts? But, again that is only a wild guess. A diode and a capacitor would have rather different connections on the board.Are there no designators printed on the board? (Like R17 or C10 or D7, etc?)What is the power supply voltage?
Memory Dumps: Datron 1072, 1081, ASL F26, Genrad 1689M, HP 3456A - Page 1
Forum section: electronics / repair

author: doktor pyta
author_rank: Frequent Contributor
timestamp: August 23, 2014, 11:46:04 am
content: HiI would like to share some memory dumps from the test equipment I own.Please let me know if these were helpful.Datron 1072Datron 1081ASL F26Genrad 1689MHP 3456AI will update this list when there will be something new.Link below:http://rfscientific.eu/memory-dump-directory
Cisco/Linksys WVC-210 PTZ camera - Page 1
Forum section: electronics / repair

author: SL4P
author_rank: Super Contributor
timestamp: August 17, 2014, 07:44:05 am
content: If anyone has one of these, it's worth pulling it apart BEFORE it fails...Mine stopped working wirelessly - but any number of problems were hiding under the plastic covers. Wired operation was still ok.Four philips screws on the rear - and you can pop the clamshell apart -You don''t need t undo the WiFi antenna connector - it can stay where it is.The problem I needed to fix was a 1000uF 6V3 electrolytic which was bulging slightly. (replaced with 10V - circled in photo)To get him out - you need to disconnect the camera gymbal and motor assembly - which revealed problem #2 - broken shock mounts. The camera had never to my knowledge been dropped etc - but three of the four rubber mountings were totalled.Depending on your circumstances - you can reconstruct the plastic lugs as needed around the rubber grommets and screws, (Photo shows how I 'ballsed it up' neatly).Massaging the main PCBs out of the case is straightforward - but you need to wriggle sideways a bit around the antenna connector.The WiFi module is socketed (DIMM - under camera assembly) onto the main board and is easy to release. I just unplugged and reconnected it to 'clean' the edge connectors.Jumpered everything back together - and all working as it should... except the main clamshell assembly screws were also toasted (one of four was holding, but plastic split).A bit of 2-part epoxy and some heatshrink sleeve (photo) around the 'plastic posts' will hold them together for a few more years.Good luck!
DS Lite. - Page 1
Forum section: electronics / repair

author: zerorisers
author_rank: Regular Contributor
timestamp: August 09, 2014, 10:41:07 pm
content: Hello everybody, zerorisers here.I have an old nintendo DS Lite. problems that I have are that the pads for the power switch are lifted and the ribbon cable for the top lcd keeps shorting. Anything that I can do about either of these problems? (ribbon cables short because of wear and tear on the plastic coating I believe, so if I have it layed out in a particular way I can get a picture.)

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2014, 02:52:13 am
content: Power switch could maybe bodged, is it momentary or off/on 2 position?For the ribbon, chop up an old PC IDE HD cable for a replacement. Assuming it is for LV?

author: wagon
author_rank: Frequent Contributor
timestamp: August 10, 2014, 05:20:50 am
content: You can buy pretty much every part for the DS off Ebay.

author: zerorisers
author_rank: Regular Contributor
timestamp: August 11, 2014, 02:41:03 pm
content: Thank you both for the reply's, I don't have much money so I am attempting a cheaper alternative. This will be for personal use. The power switch in completely gone off the board.

author: wraper
author_rank: Unknown
timestamp: August 11, 2014, 03:05:21 pm
content: Quote from: zerorisers on August 09, 2014, 10:41:07 pmIf it has damaged insulation, then you can just put a piece of insulating tape on it. If it does not help, some conductor is broken.

author: zerorisers
author_rank: Regular Contributor
timestamp: August 11, 2014, 03:07:15 pm
content: Wraper seems to have had the best idea for me personally. I will try that and see how it works once I get the power going. I'm hoping once it is fixed I can make my own "game" for it and use if for email notifications and weather on my desk.

author: zerorisers
author_rank: Regular Contributor
timestamp: August 11, 2014, 06:22:27 pm
content: My apologies to tautech for not properly answering his question, it is a on/off switch I believe.
Replacement (equivalent) for P140NF55  - Page 1
Forum section: electronics / repair

author: txescientist
author_rank: Regular Contributor
timestamp: August 09, 2014, 08:29:13 pm
content: Can someone tell me equivalent mosfet for P140NF55 in APC UPS? Can I use IRF1405?Regards

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2014, 03:04:05 am
content: Google search for "P140NF55" finds a few datasheets.Any correct substitution should match most parameters.VDS, A, RDSON, being the most important. Gate characteristics are also important when placing in a existing application to match the designers calculations.

author: mij59
author_rank: Frequent Contributor
timestamp: August 10, 2014, 05:08:08 am
content: Hi,It's better to replace with the same type, why do you want an equivalent ?The Save Operation Area of the IRF1405 is smaller, could be a problem.

author: txescientist
author_rank: Regular Contributor
timestamp: August 10, 2014, 06:41:13 am
content: Thank you for replying. I can't buy the original part in my country and that is the only problem (I could order it, but the shipping is 20-30 days and I can't wait that long).

author: wraper
author_rank: Unknown
timestamp: August 10, 2014, 07:54:19 am
content: Quote from: mij59 on August 10, 2014, 05:08:08 amActually it has noticeably bigger safe operation area than STP140NF55. IRF1405 also have a 2x max drain current and lower RDS(on). Gate capacitance few % bigger. It will work, but it is not a good idea to use it if there are any STP140NF55 in parallel. And better to get STP140NF55 anyway as it is cheaper.
Meanwell SE-350-15 Schematic - Page 1
Forum section: electronics / repair

author: German_EE
author_rank: Super Contributor
timestamp: August 09, 2014, 04:59:44 pm
content: Does anyone have a schematic for the Meanwell SE-350 series? I have one that has poor regulation and I'd like to see a circuit before I start messing around.

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2014, 03:15:57 am
content: Quote from: German_EE on August 09, 2014, 04:59:44 pmThere are many of these type SMPS PSU's available and Meanwell is only one brand.I suspect the are all quite similar. Possibly a TL494 controller?I suggest you identify the SMPS controller IC, get the datasheet and see if any of the typical applications listed match your supply. You may have to get a few datasheets of similar IC's to find what you need.

author: mij59
author_rank: Frequent Contributor
timestamp: August 10, 2014, 03:59:44 am
content: Hi,How poor is the regulation ?

author: German_EE
author_rank: Super Contributor
timestamp: August 10, 2014, 07:43:41 am
content: With no load the output is 14 volts and it is supposed to be a 23 Amp supply1 Amp load the output is 13,2 volts2 Amp load the output is 11 volts3 Amps the supply shuts down.There is a TL3845 on the primary side and a dual op amp on the secondary side, no other chips. The bridge rectifier and input capacitors are OK and I have checked the output capacitors visually. I sent emails to the Meanwell European Headquarters plus three Meanwell dealers on Thursday but a reply has yet to be received.

author: rob77
author_rank: Super Contributor
timestamp: August 10, 2014, 06:45:28 pm
content: then it's definitely not a poor regulation, but a broken power supply

author: German_EE
author_rank: Super Contributor
timestamp: August 12, 2014, 06:35:58 pm
content: There is an internal shunt and it had a dry joint on one endThe supply was trying to regulate past the shunt when under load and failing
Trying to repair my Pure Tempus-1 DAB radio - Page 1
Forum section: electronics / repair

author: deephaven
author_rank: Frequent Contributor
timestamp: July 30, 2014, 01:31:42 pm
content: My Pure Tempus-1 DAB/Alarm Clock has given me good service for several years. Then, while I was listening to a radio station on it, it suddenly made a short squawking noise for a couple of seconds and then fell silent. So now, it shows the LCD back-light but nothing on the LCD display and no sound.I took the thing apart and saw a couple of regulators and measured 3.3V on the output of one and 5V on the other, so it looks like the power supplies are still working. I had a look around the boards and noticed a crystal oscillator and this was producing the correct output. There is one small square BGA chip and I tried pushing down on that while cycling the power, but this didn't do anything. Probing around all the electrolytics, they all seem to have believable voltages across them. The AF amp also seems to be operational.Trouble is, I can't see anywhere on the web to get a schematic, so I'm working in the dark with this. Does anyone have any suggestions on stock faults or source of a schematic?

author: Smith
author_rank: Frequent Contributor
timestamp: July 31, 2014, 06:07:56 pm
content: On the interweb people report flashing the software again to fix the issue you describe.

author: deephaven
author_rank: Frequent Contributor
timestamp: August 01, 2014, 07:50:42 am
content: Quote from: Smith on July 31, 2014, 06:07:56 pmThanks for the comment. There doesn't appear to be firmware for my particular model, only the 1S

author: Jack_D_Ireland
author_rank: Newbie
timestamp: August 08, 2014, 12:34:43 pm
content: Hi deephaven,I have also come across the same issue with this model. I'm an amateur at electronics but I do like a puzzle... What I discovered at that time was that the power supply from pure (12v) was a basic heavy transformer with 4 diodes and a cap in it, one of the diodes was open and it was outputting 18-19v from memory.Inside the lcd backlight was on as you stated caps looked ok. I attached bench power supply 12v. The heatsinked LM317 got hot 60c quite quickly, assumed that's okay, but what's drawing the current? Had a look at data sheet for the TDA7266 dual bridge amplifier and noted that the voltage on pins 6 & 7 MUTE & ST-BY were above the max stated, that's as far as I got.I will try and trace the source of those voltages, I believe they originate on the front pcb.I see someone posted a Pure Evoke Flow Radio to Dave. Really looking forward to Dave getting inside this Chinese built radio...I will keep an eye on this thread.

author: deephaven
author_rank: Frequent Contributor
timestamp: August 08, 2014, 04:05:30 pm
content: Thanks for your comments, Jack. All the voltages appear to be ok. I fear the BGA chip may have failed which would be a bit of a show stopper for me. It would be nice to have a schematic so that I wasn't working in the dark, but I haven't managed to track one down so far.
Help me repair HP 3632 - Page 1
Forum section: electronics / repair

author: chihaxinh
author_rank: Regular Contributor
timestamp: August 08, 2014, 02:55:53 am
content: Dear AllI have one HP E3262 and 3 pcb in good condition (no broken - no blow IC )But :- 1 PCB Mainboard have Error 625 ( Communication with GPIB and RS 232 ) , Turn on display work ok but when i rotatry encoder for change voltage and current. Any thing not change.Voltage display in 0.0xxx V ( like reference voltage )- 1 PCB have Unreg , when power on , only CV display , don't have CC . Everything ok ( Not have error like 625 - I/O Communication Error)- 2 PCB when power on have long beep . Beep ..beep in 2 second . Display won't work- 1 PCB brokent input but we have any part in good condition to replace for Error PCBPls help me to repair and guide to me how to step by step check and fix it.Below it's link for download HP 3632 Service Manualhttps://drive.google.com/file/d/0Bz4cInwDnxUlREo5cFQxWTBTUEU/edit?usp=sharingSorry for my English , help you understand ( I live in Vietnam)Many thank you so much !My contact : namnh10@gmail.comBest regardsNam Nguyen Hai

author: idpromnut
author_rank: Unknown
timestamp: August 08, 2014, 03:41:51 pm
content: I recently fixed two Agilent supplies; the one you have with the unreg error, I would check the pass MOSFETS. In my case one of them had for sure blown, with possibly the second one blown as well. The symptom was the "unreg" enunciator on, and the measured output on the display was 0V and a very low current, regardless of the set points. I replaced the MOSFETs on my unit and everything works well with it now.
Hitachi V-423 Var controls - Page 1
Forum section: electronics / repair

author: mscreations
author_rank: Contributor
timestamp: August 05, 2014, 09:03:46 pm
content: I have a Hitachi V-423 scope that I made a horrible decision with and lent it to a "friend". When he returned it, I guess it had fallen off a bench or something and he busted the Channel 2 var knob off of the Volts/div selector. And the knob on Channel 1 looks bent.At least the thing still works normally...Now I'm trying to determine the feasibility of repairing this thing. I've been watching ebay for a dead unit hoping to pull parts, but the only ones on there are working ones (figures!) and I don't want to shell out about $180 to get this fixed. I'm purchasing a Rigol MSO2072A tomorrow, but would like to keep the Hitachi around.I haven't pulled it apart yet, I'm hoping to do that later tonight after getting the kiddos to bed. I'm hoping that I can find a number on the selector and try to get a replacement but I'm not holding my breath.Does anyone have any idea where I might be able to source some parts for this?

author: KJDS
author_rank: Super Contributor
timestamp: August 05, 2014, 09:17:40 pm
content: I've got a pile of V-552 on the shelf here, which has a very similar front panel layout. I'll check postage costs tomorrow if you let me know where you are.

author: mscreations
author_rank: Contributor
timestamp: August 05, 2014, 10:02:05 pm
content: Quote from: KJDS on August 05, 2014, 09:17:40 pmThat would be awesome! I'm in Pittsburgh, PA USA. Let me know how much and I'll see if it'll work.

author: nanofrog
author_rank: Super Contributor
timestamp: August 05, 2014, 11:02:45 pm
content: Quote from: mscreations on August 05, 2014, 10:02:05 pmFWIW, if you go into your user profile and your country, your nation's flag will display beneath your userID (US in your case). Makes things a lot easier, particularly when posting links.

author: IanJ
author_rank: Unknown
timestamp: August 06, 2014, 12:09:48 am
content: Quote from: mscreations on August 05, 2014, 09:03:46 pmAaaaarrrggghhhh, I hate hearing things like this. It is just soooooo disrespectful to borrow something and break it like this.Feel for you...........Ian.
HP 35660A DSA Repair  - Page 1
Forum section: electronics / repair

author: geo_leeman
author_rank: Regular Contributor
timestamp: August 05, 2014, 04:40:05 pm
content: I had asked this on the test equipment section, but have decided it probably belongs here instead. I was able to score a HP35660A recently, which is great considering I work with seismic equipment! I haven't ever owned/used one of these before, but couldn't pass the opportunity. I bought it "As-Is" and have been perusing the manuals.The unit powers up fine, passes all self tests, the fault log is empty, but the "Calibration in Progress" message stays on the screen indefinitely. After poking at it for a minute or so the keypad stops responding and I get "Key buffer full". I took it apart and don't see anything obviously wrong when I pulled the boards (processor, ch1, ch2) out. Any ideas on what steps to take? It's hard to probe the boards in the chassis, but if a rail was dead it shouldn't pass self tests.
power supply problem?  - Page 1
Forum section: electronics / repair

author: algorithm
author_rank: Regular Contributor
timestamp: August 08, 2014, 09:47:57 pm
content: I was curious to know if losing voltage lines on the PSU after putting a load on it is always going to be due to the board that PSU is connected with?I have a PSU that has everything correct until I plug it into the corresponding board.The ribbon cable goes into a "motherboard" with lots of SMD capacitors, etc.When plugged in, 3 of the four 5v lines is gone. the only remaining 5v line is the 1st one of the 4, under "MUTE-C". Mute-C read 12v.It is sporadically switching through things on its own, like the buttons are being pressed when they are not. Leds fade out & in.Here are the service notes. Any help is appreciated.http://manuals.fdiskc.com/flat/Roland%20JP-8000%20Service%20Notes.pdf

author: mij59
author_rank: Frequent Contributor
timestamp: August 09, 2014, 05:53:02 am
content: Hi,You could check the connectors an solder joints, e.g. CN203 etc.

author: algorithm
author_rank: Regular Contributor
timestamp: August 09, 2014, 10:15:59 pm
content: Quote from: mij59 on August 09, 2014, 05:53:02 amHi,Thanks!I will take a look at where the ribbon is soldered to the PSU board.It is confusing to me how the PSU output is perfect until I plug the PSU into the rest of the machine.I wondered if it was normal for those 5v lines to not appear, the schematic shows those four 5v lines all together.That is confusing to me as well, if those points were bridged, I would not get respective 5v readings for each wire prior to connecting the PSU to motherboard..Unless maybe the motherboard connection is at fault?Thanks again!

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2014, 02:46:47 am
content: Quote from: algorithm on August 09, 2014, 10:15:59 pmWonder if the 4 x 5V lines are this way to help faultfinding?First suspect would be shorted Tantalum caps.

author: mij59
author_rank: Frequent Contributor
timestamp: August 10, 2014, 03:46:06 am
content: Quote from: algorithm on August 09, 2014, 10:15:59 pmYes very strange, as noted by Tautech, could be a different circuit.Check with the Ohm meter if the pins are connected , and if there's a short on the motherboard.Also if there's a short IC201 should get very hot.Check the voltage at the input and output pin of the voltage regulator IC201 when the motherboard is connected.
Cateye II Nite Vision Repair. - Page 1
Forum section: electronics / repair

author: PeterG
author_rank: Frequent Contributor
timestamp: August 04, 2014, 01:39:44 am
content: Has anyone seen this model nite vision monocular?This one powers up when i press the Power button and i can hear the hv power supply singing however there is no image visible. The IR led also works.Any help would be greatly appreciated before i open this up.Regards