hybridfree/eevblog-posts huggingface dataset:
Source of .brd files for Dell Inspiron 1545 - Page 1
Forum section: electronics / repair

author: Dave Turner
author_rank: Frequent Contributor
timestamp: April 11, 2018, 03:59:56 pm
content: Hi all,I have a 9 year old Dell Inspiron 1545 with a screen fault. I have the schematics for it but have not been able to find any .brd files (or other file) openable by OpenBoardView after several days 'googling'.Anybody know of a source?cheersDave

author: RomDump
author_rank: Regular Contributor
timestamp: April 11, 2018, 05:30:44 pm
content: Quote from: Dave Turner on April 11, 2018, 03:59:56 pmI believe the Vinafix repair board has the boardview files.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: April 13, 2018, 07:12:23 pm
content: RomDumpThanks for the info.I have tried with Vinafix but to no avail. Probably my inability to search the site properly. However I'm not prepared to pay for a VIP membership without knowing that the .brd file I require is available.If anyone has any other idea please let me know.regardsDave

author: RomDump
author_rank: Regular Contributor
timestamp: April 13, 2018, 07:31:39 pm
content: Quote from: Dave Turner on April 13, 2018, 07:12:23 pmI did a google search "WISTRON DR1 ROBERTS17_DIS_-1_090519_1109 08224-1 4AQ01 DELL Inspiron 1545 " +vinafix and it appears there. Whether it is correct file is another issue. I think $10 is like the smallest VIP membership. You could probably get the file free if you do some googleing.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: April 13, 2018, 10:18:32 pm
content: RomDumpThanks again, I really appreciate your help. I'll have another look.Note it's not an updated BIOS I'm looking for but a file readable by OpenBoardView so that I can relate the schematics (which I have) to the board layout just as Louis Rossmann does on his excellent channel.ciaoDave

author: RomDump
author_rank: Regular Contributor
timestamp: April 14, 2018, 03:47:33 pm
content: Quote from: Dave Turner on April 13, 2018, 10:18:32 pmIf you scrolled further down you would have seen the boardview files. (08224-1.brd). BTW: There is two postings on that forum. One that has Schematics + Bios + Boardview and one that only has the bios. Just cut and paste my google search term into google and the first hit should be what you are looking for. You could probably just search for the boardview files on google because I posted the name in this post.
Marantz Model 1060 Amplifier transistor equivalent - Page 1
Forum section: electronics / repair

author: Rutherberg
author_rank: Regular Contributor
timestamp: April 13, 2018, 03:43:20 pm
content: Hi,I'm repairing a Marantz 1060 amplifier with a nasty noise on one channel. I isolated the fault, a pair of transistors, 2SC1000 and 2SC493 (H406, H408)What modern equivalent could I use to replace those ? I attached the schematic.Thanks

author: rsjsouza
author_rank: Super Contributor
timestamp: April 13, 2018, 03:52:28 pm
content: If NTE is to be trusted, they claim the following:2SC1000 -NTE1992SC493 -NTE87

author: oldway
author_rank: Super Contributor
timestamp: April 13, 2018, 08:39:11 pm
content: I often use bc547 and bc557 .... Be aware that the sequence of pins is not the same but just do a little acrobatics to place these transistors properly.At least, with the BC547 and 557, we are sure that it is not about counterfeit transistors and they are easily available in Europe.EDIT: This is a very common defect on the 70s Marantz.I advise you to also replace the equivalent transistors of the other channel because there is a strong risk that the transistors of the other channel present the same defect in a short time.

author: Rutherberg
author_rank: Regular Contributor
timestamp: April 14, 2018, 10:19:41 am
content: Thanks for the replies.I will go for the BC5.. solution on both channels, have it in stock.Thanks !
Need Help Finding Replacement Pot for Bass Amp - Page 1
Forum section: electronics / repair

author: 5Beans6
author_rank: Newbie
timestamp: April 14, 2018, 03:46:03 am
content: I am repairing a broken pot on a bass amp for my friend and I can't seem to find one that is the same as in the amp. I have checked most of the major electronics website including ebay and amazon but no one seems to have exactly what Im looking for. It has a value of 250K Ohms, is logarithmic, and has a D type shaft. It needs to be through hole mount because it goes into a PCB.I have included pictures of the broken one for reference.If anyone knows where I can get a replacement I would appreciate it sooo much!

author: DaJMasta
author_rank: Super Contributor
timestamp: April 14, 2018, 04:02:43 am
content: Is it just trouble finding a 250k version? That style seems to be fairly common, and the size doesn't seem to be unusual, but the stuff on digikey seems to hit at 100k and 500k and not in between. I'm certain the manufacturers would make other values, but they may not sell enough of them to keep a stock, so it may be a special order.If you can't find the right termination style, you could always bend right angle pins or trim down solder lugs to fit, or even run wires from them with them facing away from the board, since it gets all its mechanical strength from the mounting nut, having it mount directly in the PCB is sort of secondary.

author: 5Beans6
author_rank: Newbie
timestamp: April 14, 2018, 04:08:23 am
content: I think Im going to have to go with the wire method. I have found plenty of 250K pots but none with though hole mounts. Thanks!

author: car46999
author_rank: Newbie
timestamp: April 14, 2018, 04:37:36 am
content: How about this onehttps://www.jpmsupply.com/250K-ohm-Audio-Taper-Potentiometer-D-Shaft-p/60475.htm
VFD broken pins repair - Page 1
Forum section: electronics / repair

author: MrPuhur
author_rank: Newbie
timestamp: April 12, 2018, 07:13:08 pm
content: I've got this VFD as a part of a linear scale digital readout, the vacuum seems fine but the pins on one side have been broken off. The VFD is a NEC FIP10B15, couldn't find a replacement one. The way I see it, I either have to somehow reconnect wires to it or replace it with a custom pcb with 7-segment LED displays.Repair: Solder seems to stick to the tiny tips of the yellow traces still visible at the edge, though it falls off if even slightly touched. Because of this, I couldn't confirm if the solder had been conductively connected to the trace by measuring the resistance of the grid, which is the only ohmic contact between any 2 pins as far as I know. To connect the wires, I would probably have to get rid of a bit of glass to expose more of the traces, which seems rather absurd to try.Replacing it with LEDs: The VFD has a convenient signal arrangement, so it seems to lend itself to replacement with common anode/cathode LED displays, possibly with nothing but resistors to be added. I might also need to modify the driver circuitry a bit.What do you think? Is it worth to try to repair it or should I go straight to making that PCB?

author: Cyberdragon
author_rank: Super Contributor
timestamp: April 12, 2018, 09:24:46 pm
content: With that deep of a gauge, the vacuum is barely holding on. If you keep heating it with soldering or messing with that edge, it will likely vent. Something like liquid metal/wire glue might work without disturbing the seal, but if that fails you'll probably have to replace it.

author: Gyro
author_rank: Super Contributor
timestamp: April 12, 2018, 10:03:20 pm
content: The problem you're going to have, even if you can get connectivity with conductive glue or whatever, is that end connection - the filament supply. That needs to carry much more current than the rest. I'd try that one first, if you can't get the filament working then there's no point in spending time on the others.
Short-circuit locator: how sharp/rounded should the probe tips be? - Page 1
Forum section: electronics / repair

author: tggzzz
author_rank: Super Contributor
timestamp: April 11, 2018, 02:58:37 pm
content: I've picked up a "toneohm" Omnitest Hy-trak 100D audio short circuit locator, hopefully to help find short circuits on PCBs and faulty tantalum capacitors.On initial inspection it works, but the resistance readings are too variable for my liking. Having a look at the probe tips, they are not sharp pointed but are an irregularly rounded shape. See the photo.So, should the tips besharp pointed, to cut through any oxide layers, grease, flux etcrounded, to slide easily and not damage the PCB

author: SeanB
author_rank: Super Contributor
timestamp: April 11, 2018, 04:56:08 pm
content: Sharp, to get through oxide and solder resist to the copper, and if they are sharp enough to pierce the thinner varieties of copper on a PCB and leave a hole in it so be it. Round is only if you have an absolutely clean board and do not want to mark it.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: April 12, 2018, 04:57:33 pm
content: Here is some more info on the topic... This includes Bob Pease's classic detector, which requires touching the traces, as well ad Bob Smith's non-contact detector.Interesting read.http://www.pa4tim.nl/?p=5339

author: macboy
author_rank: Super Contributor
timestamp: April 12, 2018, 09:19:42 pm
content: Sharp probes ironically do far less damage to the PCB than dull ones. With dull probes, one has a tendency to push quite hard in order to make good contact, thus deforming the track/pad and potentially causing it to lift from the PCB. A needle-sharp tip only needs to gently touch the surface to break through the oxide and make good contact. A sharp tip is also far less likely to slip and potentially short out nearby pins or components.This is the exact same reason that a poorly tinned soldering iron tip, too low temperature, and/or inadequate flux can lead to PCB damage - one presses the inadequate tool into the PCB too hard, in an attempt to get better heat transfer, and this deforms and damages tracks. Add the factor of heat, and lifted pads can easily result (especially on single-sided boards).
Help with a Smd identification - Page 1
Forum section: electronics / repair

author: Elendil
author_rank: Newbie
timestamp: March 27, 2018, 03:31:29 pm
content: Hi guys, i need some help to identify a Smd 6 pin part. I know It is a n-channel mosfet but the marking Code is confusing. Perhaps some of you can help. Please see the attached picture.Enviado desde mi Aquaris X Pro mediante Tapatalk

author: Samogon
author_rank: Frequent Contributor
timestamp: March 27, 2018, 04:48:42 pm
content: It is imho general use double transistor. Cant say for sure if it is pnp or npn.

author: Elendil
author_rank: Newbie
timestamp: March 27, 2018, 05:58:13 pm
content: Quote from: Samogon on March 27, 2018, 04:48:42 pm@samogon, Thanks for your answer, but according to the electrical diagram It should be a mosfet (the one connected to the point 4P in the electrical diagram) and not a bjt transistor.Enviado desde mi Aquaris X Pro mediante Tapatalk

author: Samogon
author_rank: Frequent Contributor
timestamp: March 27, 2018, 06:57:49 pm
content: Then put some generic double package N-ch (if i see diagram correctly) mosfet like DMN3190LDW-7 logic gate it is 30V 1A should do the jobhttps://www.digikey.com/product-detail/en/diodes-incorporated/DMN3190LDW-7/DMN3190LDW-7DICT-ND/4457886

author: Elendil
author_rank: Newbie
timestamp: March 27, 2018, 07:20:35 pm
content: Quote from: Samogon on March 27, 2018, 06:57:49 pmtaking into account the PCB design, I suspect the smd should have a single mosfet inside. Some packages has one mosfet and 6 pin to handle more power. The problem is that is quite difficult to find the marking Code. The attached datasheet comes from Code 42 (readed in vertical in my smd part)Enviado desde mi Aquaris X Pro mediante Tapatalk

author: Samogon
author_rank: Frequent Contributor
timestamp: March 27, 2018, 07:36:26 pm
content: Letter D possible indication that it is double package. You have board and schematics you can track if it is singleif it turns only glove compartment light then it is single transistor

author: Elendil
author_rank: Newbie
timestamp: March 28, 2018, 07:48:50 am
content: Quote from: Samogon on March 27, 2018, 07:36:26 pmIt is for the cargo (trunk light) compartmentEnviado desde mi Aquaris X Pro mediante Tapatalk

author: Elendil
author_rank: Newbie
timestamp: April 11, 2018, 08:50:14 am
content: Quote from: Samogon on March 27, 2018, 07:36:26 pmI found It. It is the cph6445-tl-w from onsemi. Single mosfet n-channel. Marking Code ZX.Enviado desde mi Aquaris X Pro mediante Tapatalk
LG Home Cinema/Bluray Player Fault - Page 1
Forum section: electronics / repair

author: AephK
author_rank: Newbie
timestamp: April 10, 2018, 08:00:19 pm
content: Hi folks,I've only recently gotten in to electronics repair so I'm not too sure where to start with this one.Our LG Home Cinema/Bluray player (model number BH7430) has developed a number of faults. The surround speakers still work fine. As does the HDMI output, USB ports etc. However, the Wifi module doesn't work, neither does the Bluetooth nor the disc tray.I can provide pictures of the PCB if needed, but nothing seems damaged at all.Does anyone have any suggestions as to where to begin to troubleshoot this? I've tried removing the disc tray to see if that was somehow causing an issue with the other 2, but this didn't help.Any help is much appreciated!

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: April 11, 2018, 03:25:38 pm
content: Which occurred first? The tray problem or WiFi/Bluetooth problem? Doubtful they are related. The tray is likely a mechanical issue. The WiFi/Bluetooth possibly power, or chip related.

author: AephK
author_rank: Newbie
timestamp: April 13, 2018, 01:28:17 pm
content: I'm not 100% sure which happened first.Though I'd don't think it's a mechanical issue with the drive as it's motor is connected via flat flex, and when telling it to open the drive the voltage on the pins doesn't change which makes me thing there's nothing telling the drive to open, if that makes sense?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: April 13, 2018, 03:11:23 pm
content: No power to tray motor. Sounds possibly like PS. Especially if that same supply is used for BT and WiFi.Check all supplies. Likely a 5V issue. Possibly a gone south 5V regulator.
MK-328 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: March 21, 2018, 07:05:29 am
content: Hello everyone! I am looking for the software component analyzer MK-328 (see attached photo). Would someone have it? Thank you all!

author: coromonadalix
author_rank: Super Contributor
timestamp: March 21, 2018, 10:00:57 am
content: there is a big thread here :https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/

author: kripton2035
author_rank: Super Contributor
timestamp: March 21, 2018, 10:37:04 am
content: good luck reading all 100s of pages of that thread !here are the files to download:https://www.mikrocontroller.net/svnbrowser/transistortester/

author: lionelkjh
author_rank: Frequent Contributor
timestamp: March 21, 2018, 04:08:53 pm
content: thanks!

author: firewalker
author_rank: Super Contributor
timestamp: April 10, 2018, 01:28:07 pm
content: Did you find the suitable firmware for this tester?Alexander.
Help! ILX Lightwave LDT-5525 (PCB cannot be removed from custom aluminium case) - Page 1
Forum section: electronics / repair

author: ramon
author_rank: Regular Contributor
timestamp: March 24, 2018, 01:09:45 pm
content: Hi,I will need help to remove this PCB from the custom aluminium case.The case seems like a custom aluminium profile. I already dissasembled everything: front and rear panel.There are only 4 screws (which I already removed) that connects the transformer to the PCB and the bottom case.Those 4 screws are the only screws between bottom case and PCB, there are NO screws hidden behind the rubber foots.I have tried everything. And I think there are only two options:1) I am not strong enought to slide/remove the PCB from the aluminium profile,2) or I am not using the right toolDoes anyone knows If I need some custom tool for removing the PCB?

author: coromonadalix
author_rank: Super Contributor
timestamp: March 24, 2018, 01:15:24 pm
content: you have at least 4 hidden screws on your pcb preventing you to slide the board, you have 4 hex studs punched in the aluminum case, maybe the screws are silliconed or something hides them from your view ... take an top view photo

author: ramon
author_rank: Regular Contributor
timestamp: March 24, 2018, 01:31:19 pm
content: Thanks but those are the 4 transformer screws, that I already removed. There are no any other screws.

author: ramon
author_rank: Regular Contributor
timestamp: March 24, 2018, 01:33:09 pm
content: And they are not glued, as I can 'lift' the transformer and they are not attached to the hex studs. But I cannot slide the PCB even a milimeter.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 24, 2018, 01:35:23 pm
content: then you should be able to slide it in the grooves ... not pull it

author: ChrisLX200
author_rank: Unknown
timestamp: March 24, 2018, 01:48:37 pm
content: It's just tight, and the rough sides of the PCB can gall and stick in the grooves of the alloy extrusion. You need to apply adequate pressure to release and push it out. Don't try hammering it out as it will likely split - steady pressure is what is needed.

author: ramon
author_rank: Regular Contributor
timestamp: April 10, 2018, 12:40:51 pm
content: Thanks to all, I was able to remove the PCB.The aluminium base should be clamped or placed over a non-slippery surface. It is better to put the case in elevated place to apply pressure with the heigh of the body. It is important to apply pressure on the same direction as the side rail (without pressing down into the bottom, otherwise it will not move). Also I found it was better to apply pressure only in one point in the middle of PCB (than with two fingers on both sides).The fix was easy. Two red tantalum capacitors '1.5 25' (C2 and C4A) burned. I think they are only used for the fan.Maybe they burned on boot-up because the fan has so much dust. I replaced them with two miniature 4.7uF 50V electrolytic.
Looking for old Toshiba transistor datasheets: 2SB554 and 2SD424 - Page 1
Forum section: electronics / repair

author: cvanc
author_rank: Frequent Contributor
timestamp: April 09, 2018, 06:26:49 pm
content: Info on these seems to be rare, the usual Googling revealed almost nothing. Anyone got them? Thanks.

author: 4cx10000
author_rank: Regular Contributor
timestamp: April 09, 2018, 07:20:58 pm
content: Hi cvanc!What about these:http://www.datasheetlib.com/datasheet/195885/2sb554_toshiba-semiconductor.htmlhttp://pdf1.alldatasheet.com/datasheet-pdf/view/439780/ISC/2SD424.html

author: Emo
author_rank: Regular Contributor
timestamp: April 09, 2018, 07:25:09 pm
content: Hi, depending on the max voltage several can be found in a cross reference

author: PartialDischarge
author_rank: Super Contributor
timestamp: April 09, 2018, 07:26:52 pm
content: Quote from: Emo on April 09, 2018, 07:25:09 pmYou also got the Towers transistor selector book!

author: cvanc
author_rank: Frequent Contributor
timestamp: April 09, 2018, 11:38:29 pm
content: Thank you all.I remain puzzled why different people's Google searches seem to yield different results (shrugs). In any case thanks for the data sheets.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 10, 2018, 05:54:53 am
content: Quote from: cvanc on April 09, 2018, 11:38:29 pmIntentional -- results depend on context: your cookies, IP location, and so on. DuckDuckGo should be consistent (I don't know offhand if it is, but it should be, because they scrub all that info).Other than that, different people have different keyword patterns, different ideas how to search. Sometimes it can just take fresh eyes.As for old Japanese types, you probably won't find a full datasheet, but there are complete tables listing them! Here's one:https://web.archive.org/web/20031127023011/http://www.harmsy.freeuk.com/nic.percival/JpnTransistor.htmlIt's probably all been integrated into AllTransistors anyway, this one shows up:https://alltransistors.com/transistor.php?transistor=10521A good one to check firstTim
HELP identifying component - Page 1
Forum section: electronics / repair

author: ollihd
author_rank: Regular Contributor
timestamp: April 09, 2018, 08:09:55 pm
content: Hi,Does anyone know what component this is? Can't find any specs on it. It's a diode for sure, but I would like to know the specs of it. I'm repairing an power board of a late 90s sewing machine and this diode measured to be faulty.https://photos.app.goo.gl/ZAGCEFHb179lXuns1thanks in advance!

author: cs.dk
author_rank: Unknown
timestamp: April 09, 2018, 08:30:01 pm
content: IR seems to be International Rectifier, 31Q the partnumber;http://www.mouser.com/catalog/specsheets/9331931d.pdf

author: ollihd
author_rank: Regular Contributor
timestamp: April 09, 2018, 08:32:05 pm
content: You absolutely rock! Thank you!
HP5335A No input error 7 - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 09, 2018, 11:35:51 am
content: Picked up a HP5335A Saturday and after a few quick tests I notice I am not getting a signal through the A or B inputs.Before opening this unit I wonder if anyone has experience in 5335A not recognizing input to A or B.Passes start-up self test.Running Special Diagnostic returns Error 7.Unit has Options 010 High Stability and 030 C Channel input.Channel C works fine.10Mhz signal on back panel outputs 10Mhz.Thanks

author: Dr. Frank
author_rank: Super Contributor
timestamp: April 09, 2018, 12:09:55 pm
content: Error 7.0 has something to do with self testing routines, and indicates a missing cable from rear oscillator output to Input.Please check, whether the rear EXT ARM switches are both set to zero.The input amplifier and trigger circuit seems to work, as the trigger LED is lit.What about the Gate LED?Frank

author: DimitriP
author_rank: Super Contributor
timestamp: April 09, 2018, 12:47:42 pm
content: QuoteTo try measuring using the B input you have to select the B input; press: Scale, Smooth, 17, ENTERFeed it the 10Mhz reference from the back and it should display 10.000.000 with the Gate control mostly counter clockwise

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 09, 2018, 12:55:37 pm
content: DimitriYes, that got channel B working Reads 10.000.000 +6

author: Johnny10
author_rank: Frequent Contributor
timestamp: April 09, 2018, 02:49:00 pm
content: OK,So I take off case top, remove cables going from input board to mainboard, check for signal.A and B have signal to mainboard, Good.Put connector back on and tighten, now I have both channels working.Loose connector!Yes...
Bench Power Supply - Repair / Schematics - UG-6010DC or Axiomet AX-3003L-3 - Page 1
Forum section: electronics / repair

author: jozamm
author_rank: Newbie
timestamp: April 07, 2018, 12:24:39 pm
content: Dear all,I am in process of repairing a bench dual power supply of the type UG-6010DC or AX-3003L-3. (Link :https://grobotronics.com/power-supply-laboratory-3-channels-0-30v-0-3a-axiomet.html). These are standard models found in labs, 2 variable output supplies (variable current and voltage) with Master/Slave control and a 3rd 5V fixed output. These models are 30V, 5A per channel and 5C,3A. (Image at the end).I would appreciate if anyone has the schematic of such model or a similar model to help me in its repair, I believe that there is a standard schematic around with different variations,Thanks beforehand,jozamm

author: coromonadalix
author_rank: Super Contributor
timestamp: April 08, 2018, 05:05:11 pm
content: hum i think they ressemble some mastech models, there's a few schematics on the web ... but linears models, if yours is switching as i think it is, i did not see them or searched them ...

author: oldway
author_rank: Super Contributor
timestamp: April 09, 2018, 08:22:40 am
content: http://farhek.com/jd/1aw11121/supply-mastech/11st211/
Help with Tektronix 2213 repair - Page 1
Forum section: electronics / repair

author: soundaudiorepair
author_rank: Contributor
timestamp: April 03, 2018, 10:17:57 pm
content: Hi All,My oscilliscope broke. It no longer displays anything on the crt display. It still hums when I turn it on.I got the service manual and started working through the troubleshooting flow chart.The Low Voltage Power rails were all half of what they should be, except for the 5v rail which was about .25v.The next step was measuring voltage across VR938, with pins 1 and 2 of U931 shorted, while bringing up on a variac to no more then 85VAC RMS. It should be around 42v, I have 15v.The current step is shorting the base of Q956 to TP934 and checking that voltage again.But I don't have a TP934 on my board. I see it on the physical layout diagram but it is not in that spot on my unit. Also my service manual appears to be missing schematics for the power supply, I just have a parts list. So I can't look up what would be equivalent to TP934, or figure out which leg of Q956 is the base.Please help me proceed. This is the service manual I'm working from:https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjbov35jp_aAhWrq1QKHfyGDfAQFggnMAA&url=http%3A%2F%2Fw140.com%2Ftektronix_2213_service.pdf&usg=AOvVaw33NZRDPHQKrBMCF3sph-zo

author: cheeseit
author_rank: Regular Contributor
timestamp: April 05, 2018, 12:47:18 am
content: FromKOBB,thisSM is 13 pages longer and I believe it has the PS schematic you need on page 206-207.

author: soundaudiorepair
author_rank: Contributor
timestamp: April 05, 2018, 12:59:20 am
content: YES! Thanks you so much.Sam

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 08, 2018, 04:54:24 pm
content: Hi!QuoteI can think about buying one as a project now there's a complete S.M. with all the pages in it!Chris Williams
Voltage Detector: What output signal to expect? - Page 1
Forum section: electronics / repair

author: laus
author_rank: Contributor
timestamp: April 08, 2018, 05:21:26 am
content: I've been tracing down potential issues and noticed that the output pin (OUT) of the S-80841CLY-B voltage detector always reads zero. The voltage input (VDD) is at 5V. Ground (VSS) goes straight to ground.The only way to test an input voltage below 4.1V is to turn on/off the device. When turning off there is a nice curve on oscilloscope for the VDD pin as the voltage drops down but the OUT pin stays solidly at zero volts. I'm not sure what kind of output I should expect below 4.1V and at/above 4.1V. The data sheet unfortunately didn't help me.

author: Ian.M
author_rank: Super Contributor
timestamp: April 08, 2018, 06:48:34 am
content: That product code has a CMOS (push-pull) output, a 4.1V threshold and 0.2V hysterisis. Pages 23 onwards describe its operation. If its output is low with 5V on its Vdd pin, its dead, Jim. Check the output line isn't shorted to ground before fitting a new one.

author: laus
author_rank: Contributor
timestamp: April 08, 2018, 04:53:18 pm
content: Thanks Ian. That helped me a lot. With your help I reread the data sheet and it makes now more sense. The output isn't shortened, so this faulty voltage detector is most likely the issue.
Signal Generator R&S SMIQ  Labels in the schemes - Page 1
Forum section: electronics / repair

author: Aleksandar
author_rank: Contributor
timestamp: April 05, 2018, 12:06:25 pm
content: Hi everyone,Does anyone know what these labels mean in the brackets below the functional tag, in the schematic for the 6GHz module?For example: TP5100_ON and below (1 / 4B, 2 / 3B, 16 / 4C)?Thanks in advanceAleksandar

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 05, 2018, 07:22:15 pm
content: Hi!I think they may be simply page or diagram nos and co-ordinate references! Where a number/reference is repeated on any particular diagram port, this means that particular port is fed from/to all the referenced sections, i.e., connected together!I've just looked at the "6GHz Extension Service Manual" ref 1084.9600.02 on k04BB and this confirms it - the figure before the stroke is the "Blatt No" (German for Fig. No!) which you'll find in the bottom corner of the title block of each drawing, with a '+' sign following, whilst the figure/letter after the stroke is the co-ordinate square the signal port, reference, etc., is found in!Is that document the one your query referred to?Chris Williams

author: Aleksandar
author_rank: Contributor
timestamp: April 06, 2018, 06:22:19 am
content: Hi Chris,Yes, that document is in question.Your comment is the right explanation for my question.You helped me a lot.Thank you very much.Aleksandar
Anritsu S331D / S332D / S810D / S820D / MS2711D HELP!! (LCD Cable Info) - Page 1
Forum section: electronics / repair

author: eb4eqa
author_rank: Regular Contributor
timestamp: October 06, 2017, 09:41:53 am
content: Hi. I am trying to repair an Anritsu S332D that arrive in pretty bad shape. The analyzer seems to be alive and working because I can take screen dumps with the MasterSoftwareTools via serial port (see attachament of a 750MHz, -20dBm signal).The problem is it arrived with a crashed TFT and (worse) some missing pieces. The most critical being the cable I've been looking to the LCD datasheet and the signals on the motherboard and they don't even seem to be compatible. Someone has pointed to the LCD "cable" having electronics in it. Those are terrible news...It is also interesting to note that the LB064V02 LCD display has a CCFL connector that is a lot smaller than the one on the motherboard. The cable may also contain a way to adapt the diffent power connector for the backlight.Does anyone have information (pinout, wiring, pictures, etc).. on this cable assembly. Any information will be greatly appreciated.I am attaching a few pictures that might be of interest.Thank you,Roberto

author: kjk24
author_rank: Regular Contributor
timestamp: April 06, 2018, 04:30:57 am
content: Hi i have a same issue the tft dst is bad nothing on the screen is showing, and no cable inside the case? someone try to fix it without succes. It has to connector for a color and a dstn display i think the fpga can handle both and switch to the right mode but how? My one drives default the older dstn screen with 640*480. (i measured the pixel clock etc. on the sockets, both sockets are shared). the black is for dstn and the white 31pin is for color display.Habe you a cable for the 31 pin connector? That would help a lot. i beleive the switching between the modes is made by a jumper bridge on the flat cable.best regardskai
How to make Agilent 4287A Probe Header - Probe Test Fixture - Page 1
Forum section: electronics / repair

author: chihaxinh
author_rank: Regular Contributor
timestamp: April 06, 2018, 02:55:20 am
content: Hi everybodyI have one Agilent 4287A - RF LCR Meter but missing Probe Header - Probe Test FixtureThe probe very expensive , and my work not using test to high frequency . So How can make diy probe for Low frequency from 1Mhz to 100Mhz . I checking N plug outer RF and Input 1 - Input 2 port it's short .You can see picture and it's correct way make probe pcb and correct measurement method ?Many thank so much !Nam Nguyen Hai
Samsung TV LE37R87BD - Page 1
Forum section: electronics / repair

author: jtu
author_rank: Unknown
timestamp: April 01, 2018, 09:23:27 am
content: My mother in law bought new TV, old one was totally dead. I could not restrain myself from opening it upNo lights, not even power-on/stand-by, not responding to anything was meant by totally dead.Opening it showed the obvious: caps. Several were bulged, couple were blown. I replaced the caps.Now it shows some signs of life, but still not working condition. Power-on/stand-by seem to be functioning properly, there are sounds when menu buttons are touched. Screen does one white flicker very weakly couple seconds after power-on (see ~1:17 in the video).Video in the galleryhere.Power rails seem ok. I checked if 24V rail going to CCFL does not go down when screen does it's single flicker. It does not alter.Audio processor chip SGTV5810C feels quite hot. But I can still touch it for at least few seconds.That's it for the first approach. I will think of the next step. If I'll wake up with an idea or google it or somebody suggests something. Or just move it to the dumpster. Not that I need another (old) TV screen.

author: Rasz
author_rank: Super Contributor
timestamp: April 01, 2018, 02:59:03 pm
content: ccfl and big gauges in the screen = dumpsterbut the problem you describe sounds like ccfl inverter shutting off due to protections, might be one of transformers being shorted/open/lowered resistance, or lamp dead

author: jtu
author_rank: Unknown
timestamp: April 01, 2018, 05:06:05 pm
content: Big gauges? Sorry, english dictionary did not help meIf white spots on the screen are meant here, it’s just some dirt.CCFL were my next guess also.

author: Rasz
author_rank: Super Contributor
timestamp: April 01, 2018, 07:26:04 pm
content: that dirt totally looked like holes

author: vinceroger
author_rank: Regular Contributor
timestamp: April 02, 2018, 01:00:19 pm
content: Hi im not sure if your a member on badcaps.net but if you are start a thread on there too and we can help you fault find etchttps://www.badcaps.net/forum/search.php?searchid=10236003

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 01:29:38 am
content: your psu cap are buldged, some of them ae leaking too, do an psu recap first, check for cold joints too in the psu, is the tv worth repairing to youyou may undergo small or big problems if caps have failed

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 01:32:18 am
content: find this :https://www.manualslib.com/products/Samsung-Le37r87bd-438035.html

author: jtu
author_rank: Unknown
timestamp: April 05, 2018, 09:25:54 pm
content: Quote from: coromonadalix on April 04, 2018, 01:29:38 amCaps replacement was first thing I did. I wrote that in OP.

author: jtu
author_rank: Unknown
timestamp: April 05, 2018, 09:28:11 pm
content: Quote from: coromonadalix on April 04, 2018, 01:32:18 amwow, this seem very good read for me!PS Value for me lays not in the TV itself, but in the learning while fixing. Or destroying
Schematics or SM for Advance Hiflex HI750 PSU - Page 1
Forum section: electronics / repair

author: dexters_lab
author_rank: Unknown
timestamp: April 05, 2018, 07:36:11 pm
content: I don't suppose anyone has any technical info like schematics or a service manual for the Advance Hiflex HI750 modular PSU do they?
1 Wire Communications not sure on a couple of these components - Page 1
Forum section: electronics / repair

author: marty
author_rank: Contributor
timestamp: March 30, 2018, 11:27:52 pm
content: Sorry having ISP issues trying to upload a photo.To replace this board/UI is $270.00 and that's insane but anyways.This is from a Kenmore Series 600 Washing machine User Interface. No idea why it just stopped working the UI panel appeared dead (3 year old machine).I tested the fuse and it was good.Replaced the Control board (170.00 + 30 shipping). as it was completely covered in something and no access to anything other than the fuse sticking out.The new board did the same thing. I finally figured out how to access the diagnostics after a painstakingly long internet search.The UI panel completely lights up, buttons and speaker works.Diagnostics says F6 E2 (Control board to UI panel communications error).. Troubleshooting says wire harness, it's 0.2 Ohm each wire. Could not find any trace problems either. I can only assume 1 to 3 components are dead. Tech support lol, I told them I replaced the control board and he said, well then it's not the control board and provided nothing else of value like diagnostics, led flashing on control board rapidly then 1 per second.Right from the start this UI board has Lelon capacitors. VHZ Series.. Nice premium priced washing machine for subpar parts.Trying to understand how the communications work here and a little puzzled by YV6AG (U13)I believe KL1 D1 is BAT54 single schottky diode, this tested good.ZV5wA unable to find specific chip information.MCU is STM32 F071CBT6Pin 21 PB10 SPI2_SCK,I2C2_SCL,USART3_TX, CECTSC_SYNC, TIM2_CH3Pin 22 PB11 USART3_RX,TIM2_CH4, EVENTOUT, TSC_G6_I01,I2c2_SDASo this does Single-Wire Half-Duplex communication on USART3 with tx on pin21 and rx on pin22. I assume U13 turns off or on depending on tx/rx communication?I have yet to attach the scope as I would like to know what or how this thing works before doing so.I drew the line for the traces on the picture along with chip codes.Thank you.

author: marty
author_rank: Contributor
timestamp: April 04, 2018, 04:26:50 pm
content: I have the washer working.Desoldered the diode and soldered it back on.Ran diagnostics left it in diagnostics mode flashing F6 E2 while I talked (5 mins or so), pressed power and it came on.I think this issue might come back as 1-wire communications is difficult as it is on a single PCB (at least from my reading), not to mention trying to pass it over a 6 inch wire through a ferrite to a separate board.I wonderedDid the crystals drift. (time,vibration,temp., settling)The power was clean enough. was pretty steady 5.054 volts If I recall there was +- 300 or so microvolts changeNoise on 1-wire line.I think it may have been a better idea to use 2-wire instead with more margin for errors. Yes a little higher production cost a 6 inch wire and 4 pin connectors and 1 more trace all of which there was enough room for.anyways that's my opinion, so time will tell now.
Tektronix 2213 power supply schematics - Page 1
Forum section: electronics / repair

author: soundaudiorepair
author_rank: Contributor
timestamp: April 05, 2018, 12:47:51 am
content: Hi All,I'm trying to fix my Tektronix 2213 oscilliscope, but I cannot find schematics for the power supply and current limit board.Every version of the service manual I've found is just missing them. I found one thread on here where someone uploaded an image of it, but my unit has the A19 Current Limiter board instead of the A18 Preregulator board so it was not the same circuit.Tektronix does not have it. Anyone out there have it and can scan? Or can point me to it on the internet?Sam

author: soundaudiorepair
author_rank: Contributor
timestamp: April 05, 2018, 01:00:35 am
content: nm. someone gave it me on another thread. Thanks
Noticed something strange while repairing keyboard - Page 1
Forum section: electronics / repair

author: ZedRedLed
author_rank: Contributor
timestamp: April 02, 2018, 04:03:01 pm
content: Hi,I recently posted on here about a keyboard I was trying to repair. Some of the keys were connected to each other after a spillage.Today I was looking for the cause of this, when I noticed something I don't really understand.When I connect the membrane trace that is causing problems to one end of a wire with a ferrite bead that is connected to a capacitor near the LEDs on one side and to the membrane and microcontroller on the other, It works absolutely perfectly for about 5 minutes.After that it goes back to keys being connected or one key being pressed infinetely (always the same key)What could be causing this? I'm thinking perhaps a bad capacitor, but I don't know how plausible this is.P.S.: I circled the ferrite bead in the picture of the circuit, I connect the trace with the bottom pin for the 'reset'

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: April 03, 2018, 08:42:54 am
content: What keyboard is it?It looks like one of the Logitech K series, maybe K800.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 12:46:33 am
content: thoses are jumper wires between 2 traces, if they have some ferrite around them, its for noise killing, supply noise, or keyboard scanning etc ...it goes to the white sticker microcontroller, seems to be programmable

author: ZedRedLed
author_rank: Contributor
timestamp: April 04, 2018, 08:10:10 am
content: QuoteIt's a Madcatz V7

author: ZedRedLed
author_rank: Contributor
timestamp: April 04, 2018, 08:13:05 am
content: QuoteYeah, I'm even wondering if the problem could somehow be software related, although I kinda doubt it.I wonder what would happen if I permanently connect the trace with this jumper, although a "proper" fix would be better

author: ZedRedLed
author_rank: Contributor
timestamp: April 04, 2018, 08:19:29 am
content: Hereare some pictures from the other side of the same PCB. There was some damage at the circled ferrite bead and at the capacitor (to the right, next to the 6 pin connector on the original picture)

author: Rasz
author_rank: Super Contributor
timestamp: April 04, 2018, 04:55:47 pm
content: sooo, it never occurred to you to clean it up?buy new keyboard

author: ZedRedLed
author_rank: Contributor
timestamp: April 04, 2018, 08:23:05 pm
content: Cleaning it up was the first thing I did, the pictures are old and meant to give an idea of the damage.I also have enough keyboards, I just want to fix this one

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 09:59:33 pm
content: its definitely an noise cancelling filtering ferrite, if the jumper is good and cleaned the keyboard still should work ?? unless some unknow damage occured while powered, fried cpu etc ...
Dse Q-1802 oscilloscope  - Page 1
Forum section: electronics / repair

author: oneKone
author_rank: Newbie
timestamp: October 06, 2016, 04:08:47 am
content: Hi, long time lurker first time poster! And like many first posts this is going to be a question....I recently bought two dick Smith branded Q-1802 20mhz oscilloscopes. From what I can find its the same as a pintek ps-200. Unfortunately one of them doesn't work due to a resistor. I'll admit i haven't tried tracing the circuit but I have replaced the resistor with no luck. I was wondering if someone had a schematic of this scope laying around, for the life of me I can't seem to find one.The resistor in question is R428.Cheers,ChrisSent from my SM-G935F using Tapatalk

author: singapol
author_rank: Frequent Contributor
timestamp: October 06, 2016, 04:27:14 am
content: Pintek 200 service manual is here: Heatkit SO-4552 scopehttp://www.badcaps.net/forum/showthread.php?t=13252From this link originally :https://www.eevblog.com/forum/repair/missing-high-voltage-in-crt-osc/Hope it's not the high voltage transformer.

author: oneKone
author_rank: Newbie
timestamp: October 06, 2016, 04:39:28 am
content: Mate your a legend! I swear I've looked everywhere for a schematic.Sent from my SM-G935F using Tapatalk

author: oneKone
author_rank: Newbie
timestamp: October 07, 2016, 11:59:43 pm
content: Quote from: wilfred on October 06, 2016, 09:47:56 amCheers for the heads up, I didn't even realise I titled it wrong.Sent from my SM-G935F using Tapatalk

author: oneKone
author_rank: Newbie
timestamp: October 08, 2016, 12:27:40 am
content: i done some probing around on the board and it seems a voltage regulator and two transistors are dead. luckily pintek replied to a email i sent and have given me a full schematic, i didn't think it would be that easy to get a schematic for a product? now i feel like i have a decent chance at fixing it. unfortunately i can't attach the pdf files because of the size limit but i will be happy to email them to whoever needs them, ill also keep a backup on my nas. looking forward to posting updates!!

author: Agent24
author_rank: Regular Contributor
timestamp: April 04, 2018, 07:37:33 am
content: Quote from: oneKone on October 08, 2016, 12:27:40 amI don't suppose you happen to still have that schematic? I could do with a copy. Thanks!
Farnell C1 bench power supply - Page 1
Forum section: electronics / repair

author: SgtTech
author_rank: Contributor
timestamp: November 02, 2016, 09:24:29 pm
content: I have been searching for documentation about the Farnell C1 power supply. I recently picked one up cheap. It works fine apart from the current meter not registering anything. The voltage output meter matches my multimeter so thats cool. I do not know anything about the specs of this power supply and would welcome any information from the forum members about the unit itself or where I might find a manual. I have looked through the manual links on the eevblog forum but with no luck so far.

author: singapol
author_rank: Frequent Contributor
timestamp: November 03, 2016, 04:14:24 am
content: Try this:http://www.collection.archivist.info/searchv13.php?searchstr=FarnellScroll down to IS595.

author: SgtTech
author_rank: Contributor
timestamp: November 03, 2016, 07:28:31 pm
content: Thanks for that I have emailed Dave to see if he has the documents for scanning. I'll let you know how I get on.Ian

author: SgtTech
author_rank: Contributor
timestamp: November 04, 2016, 08:10:46 pm
content: Just to let you know Dave has come through for me and I know have a full scanned manual for the PSU complete with schematic so now need to get on a trouble shoot the thing. Its going to be a few weeks before i can do this, work gets in the way.Talks again for helping me find this.Ian

author: toastedcrumpets
author_rank: Regular Contributor
timestamp: December 08, 2017, 02:01:27 pm
content: I know its been a year, but is there any chance you could forward the scan of the manual onto me? I have one which seems to work, but I need a replacement output fuse. Not sure what the size is though....

author: SgtTech
author_rank: Contributor
timestamp: April 03, 2018, 06:13:22 pm
content: Apologies for not responding before do you still need access to a copy of the Instruction book?Ian
Mackie CR1604VLZ mixer channel gain problem - Page 1
Forum section: electronics / repair

author: belzrebuth
author_rank: Frequent Contributor
timestamp: April 02, 2018, 10:29:18 pm
content: Hi all,My mixer recently developed signal gain loss on 3 channels.The trim pots (input signal gain pots) of channels 7, 12 and 15 did not work at all.Signal was passing thru but no gain adjustment whatsoever.I disassembled the mixer and spilled some isopropyl alcohol with a syringe on the top of the trim pots (where the shaft meets the body of the pot) exercised them well and that seemed to fix the issue.I then put the mixer back together.(it's a real pain to disassemble btw)I was happy with it for a couple days until I noticed that the trim pot of channel 15 is dead again.At first I suspected the trim pot itself but the problem occurs 10-15 minutes or even less after I turn on the mixer.Initially the trim pot works as expected and then completely stops working.One time I've heard the signal gradually losing gain but I'm not sure if it does that consistently.I think the trim pot can also suddenly stop responding.Since it's very space consuming having this mixer opened up on my desk I thought I should post here first before opening it up again..I've attached schematics of the input section.

author: Hornethandler
author_rank: Contributor
timestamp: April 03, 2018, 05:29:20 pm
content: I have the same mixer. They are known for having intermittent connections at the ribbon cable connectors.I've fixed mine a couple/three times now in the past 15 years or so. Remove the cover on the bottom of the unit (a cover plate about 10"x4"); it's held on with 4 screws. You'll then have access to all the ribbon cable connectors (6 or 8 if I remember). Disconnect one at a time and and spray with contact cleaner. This has always fixed my low signal and intermittent problems.Good luck and let us know how you make out.