hybridfree/eevblog-posts huggingface dataset:
Service Manual for Toshiba Satellite Pro A300 - Page 1
Forum section: electronics / repair

author: ozwolf
author_rank: Regular Contributor
timestamp: February 09, 2016, 10:21:02 pm
content: Hi All,I did a search online and on the EEVBlog Forum looking for a service manual for Toshiba Satellite Pro A300 Model #PSAGDA-03E00R.This laptop has been my daily driver for many years and it has finally decided that it wants a new CMOS Battery.I'm looking for two things;can anyone confirm the CMOS Battery is a Sony ML1220?if a copy of the service manual is available, I'd be very appreciative.Ozwolf

author: AlfBaz
author_rank: Super Contributor
timestamp: February 09, 2016, 11:14:22 pm
content: Have a look at what Toshiba have said to this guy (scroll down to the Toshiba section)http://www.tim.id.au/blog/tims-laptop-service-manuals/If you PM me your email address I can send you a schematic for a TOSHIBA Satellite A300 - Quanta BL5S SANTA ROSA - Rev 1ANot the same but it may be close enough.Unfortunately it's 1.15MB and there's a size limit of 1MB for attachments

author: ozwolf
author_rank: Regular Contributor
timestamp: February 10, 2016, 01:25:05 am
content: Thanks AlfBaz, I'll PM you with the email address.Yes, I did come across his webpage and became very disappointed with Toshiba's policy. It may affect future purchasing decisions on my part.Ozwolf

author: amyk
author_rank: Super Contributor
timestamp: February 10, 2016, 12:15:31 pm
content: Or you could just Google "Quanta BL5S"...The CMOS battery is not critical, any 3Vrechargeableof roughly the same capacity should work. The charging circuit is very simple.

author: AlfBaz
author_rank: Super Contributor
timestamp: February 10, 2016, 02:00:18 pm
content: In case anybody else wanted the file, it and many others are herehttp://www.edaboard.com/thread210455.htmlYou have to sign in to see the attachments thoughI posted the above link some time ago in the "Repair Documents and Links..." thread in the repair section

author: ozwolf
author_rank: Regular Contributor
timestamp: February 10, 2016, 10:28:14 pm
content: Thanks for your help, AlfBaz.Ozwolf

author: ozwolf
author_rank: Regular Contributor
timestamp: February 14, 2016, 05:32:24 am
content: Quote from: amyk on February 10, 2016, 12:15:31 pmWell Amyk, that was the hint I needed I guess.Went to Vidcam (a Jaycar authorised dealer) and couldn't get the exact battery I wanted but did pickup a Panasonic VL2020-1VC. After dismantling the laptop, discovered the existing battery on motherboard was a much smaller diameter (10mm). In the end, I ran some twisted pair out of the motherboard into a spare cavity accessible without dismantling laptop case for "next time".Ozwolf
SMD component identification - Page 1
Forum section: electronics / repair

author: ElectricGuy
author_rank: Regular Contributor
timestamp: February 02, 2016, 03:12:29 pm
content: Hi;Can somebody help me confirm that the component on the red circle of the image is a SN74LVC1G3157.The component is marked 3157 and is placed in a TFT display board.IT gets really hot, over 160º measured with a "special edition" Flir E4, and if i freeze it with freeze spray the display board works.Also, is the package SC-70?Thank you.

author: pmichel
author_rank: Contributor
timestamp: February 03, 2016, 12:40:57 am
content: The part might be SGM3157 (datasheet shows 3157 as the marking instead of C5 on the other P/N), but comparing the two datasheets they look similar enough to probably be interchangeable.http://en.sg-micro.com/index.php?m=default.products_show&id=188

author: pmichel
author_rank: Contributor
timestamp: February 03, 2016, 12:44:36 am
content: That would also match the SC-70 package too.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: February 03, 2016, 11:08:42 am
content: Thanks

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 03, 2016, 11:47:36 am
content: Quote from: ElectricGuy on February 02, 2016, 03:12:29 pmSo probably the part is not broken but heavily overloaded?

author: ElectricGuy
author_rank: Regular Contributor
timestamp: February 13, 2016, 11:19:35 pm
content: Just an uptdate.!Changed the part and it works great now!
Trying to identify a few components AudioTechnica ANC9 - Page 1
Forum section: electronics / repair

author: Muxr
author_rank: Super Contributor
timestamp: February 20, 2016, 12:28:46 am
content: Trying to repair a pair of noise cancelling headphones. Can anyone identify the two ICs in this picture:They seemed to be made by National Semiconductor (or at least the logo looks that way), but I am not able to find any datasheets for these parts.
Image sticking/persistence Samsung LCD - Page 1
Forum section: electronics / repair

author: edy
author_rank: Super Contributor
timestamp: February 15, 2016, 06:08:49 am
content: I have a Samsung LCD TV from 2008 which is starting to show significant image sticking. Some history on this TV... I had to change the caps on the TV power supply only a couple years in and have had no other issues since. (Famous power on clicking issue)But I just started to notice the stuck ghost recently, and it only takes a few minutes to stick. Eventually it goes away once I resume watching a moving picture. For example, if I pause TV or have a menu up for a couple minutes, when I jump to another channel or resume playing, I see the previous image faintly still on the screen depending on how bright the image and colors.Any idea what is going on, what could be the culprit? Remember the ghost image only needs a minute to form... not hours like you hear from image burn.

author: wraper
author_rank: Unknown
timestamp: February 15, 2016, 07:16:18 am
content: Try this test (requires native resolution)http://www.lagom.nl/lcd-test/inversion.phpprobably positive and negative voltage applied to the pixels (polarity is being inverted on the each refresh) are not equal.Any image post processing preferably should be disabled to not mess up the test.

author: bktemp
author_rank: Super Contributor
timestamp: February 15, 2016, 07:38:41 am
content: It could be the VCOM/gamma buffer or some other local power supply for the LCD panel. They are all located on the TCON board.

author: amyk
author_rank: Super Contributor
timestamp: February 15, 2016, 11:06:22 am
content: Do you see any smearing in moving scenes? I agree with the others here, seems like Vcom isn't right or perhaps not sourcing enough current.

author: edy
author_rank: Super Contributor
timestamp: February 15, 2016, 02:00:10 pm
content: Normal TV seems ok, at least for now. Maybe not bad enough yet to notice. I just don't want to risk if I neglect it until it's too late and end up having more damage.I am not surprised that it could be a power supply issue. This era of Samsung was notorious for it, and I was affected by the "power on clicking" fiasco that was class action settled. Except being in Canada I was out of jurisdiction and just changed the faulty caps myself for $5 and swore never to buy another Samsung again.So this 2008 TV should have died 2010 and now it is 2016. Perhaps time to look at all caps again?
Rigol DG4102 Fun Gen output damaged by voltage overload - repaired - Page 1
Forum section: electronics / repair

author: tony t
author_rank: Newbie
timestamp: February 12, 2016, 08:16:40 am
content: Accidently applied 24V to the output of my Rigol DG4102.“OverLoad protect, The output is off!” appeared. I disconnected everything, powered cycled the unit but the output system is damaged. Output is about at 80% level and weird offset voltage on output.Looked at the rear side of PCB and measured all the resistors between channel 1 and 2 but cannot determine which component is bad. All components physically look okay.Any advise?

author: han
author_rank: Frequent Contributor
timestamp: February 12, 2016, 08:33:56 am
content: 1. Try warranty first2. If Warranty is not covered or the shipping is to expensive and you want to repair your own:-Check the signal path backward, find where the signal start to distort-Probably the diode limiting protection is damage and shorted.

author: tony t
author_rank: Newbie
timestamp: February 12, 2016, 09:39:50 pm
content: Okay, problem fixed. Channel 2 working again.Found a burnt out resistor, 31.4 ohm see image.Replaced with 51 & 82 ohm 0602 resistor - 31.4 ohm
Rohde &Schwarz  APN 62 keyboard  problem  - Page 1
Forum section: electronics / repair

author: Simon Spiers
author_rank: Regular Contributor
timestamp: February 12, 2016, 08:22:36 pm
content: Hi all. I have just bought a R&R APN 62 LF sig gen in non working condition.The unit powers up but I have no control from any keyboard button other than the rotary encoder. The unit is stuck on the termination adjustment which seems to work fine but that's all I can do.The generator is outputting a waveform so it looks to me like the CPU is working fine.I have looked at the only chip that has any logic on it regarding keyboard entries and that is a NEC 71055 parallel interface unit.Logic can be seen on pins 1 thro 4 and 39 and 40.There seems to be no change to any other pins on the chip.I have changed this IC thinking it may be the problem but it's not.No manuals are available unfortunately.Any ideas pointers or help would be greatfully appreciated.
Fluke 2176A Repairing? - Page 1
Forum section: electronics / repair

author: thejoggingmat
author_rank: Regular Contributor
timestamp: January 27, 2016, 12:27:41 am
content: Hi, does anyone have experience in repairing a Fluke 2176A, or a copy of the repair manual? I won one at an evilBay auction for a dollar. It's marked as 'does not turn on'. Currently in a freight forwarder in US.

author: thejoggingmat
author_rank: Regular Contributor
timestamp: February 12, 2016, 03:49:40 am
content: bump upAnything?

author: tautech
author_rank: Super Contributor
timestamp: February 12, 2016, 06:55:02 am
content: Quote from: thejoggingmat on January 27, 2016, 12:27:41 amCould it be a rebadged Phillips from shortly after Fluke acquired Phillips?
Mica Paper Alternative for heat element replacement on rework station - Page 1
Forum section: electronics / repair

author: dp121287
author_rank: Newbie
timestamp: February 09, 2016, 01:53:56 am
content: I got one of these rework stations. They were working great until the heating element died. I was included a spare with my packaging but it didn't come with the "mica" paper. The mica paper seperates the heating element from the wand from shorting out.I tried wax paper, and paracement paper but it just burns through it.Just wondering what everybody else uses.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 09, 2016, 01:56:04 am
content: Glass woven fire blanket?

author: SAGOLSEN
author_rank: Contributor
timestamp: February 10, 2016, 03:57:22 am
content: Is anything preventing you from re-using the original mica sheets? You can always buy new ones but it's hard to see why that'd be necessary.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: February 10, 2016, 04:23:59 am
content: Asbestos?
Need help identifying a zener diode - Page 1
Forum section: electronics / repair

author: tobor
author_rank: Contributor
timestamp: February 08, 2016, 03:41:26 am
content: So, I'm refurbishing my AR X-06 receiver, and on the main power supply board, there is a broken zener diode. The service manual references is as a UZ-20 (M, H) Zener Regulator. That's not enough information for my limited experience to figure out what the appropriate specs for a replacement would be.I'll attach the schematic for the board as well as a photo. It is component D903. D904 is an identical component, so, one solution that comes to mind, would be if I could determine through testing what the specs are on D904. However, if I do so, I need to be careful not to destroy it as well.Any help, on either a direct ID from the description, from it's use in the circuit, or on a method of determining the specs of the good component with little or no chance of damaging it, would be greatly appreciated!
Conformal coating removal  - Page 1
Forum section: electronics / repair

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 05, 2016, 07:38:44 pm
content: I did some googling came up with some incomplete , but professional sites , they gave a good outline on procedures , but very little on solvents .From what tell the coating I have on a project and using this site , it mostly likely seems like type of silicone .http://www.circuitrework.com/guides/2-3-1.shtml
Where is the TEK 2245A backup battery? - Page 1
Forum section: electronics / repair

author: AndersJ
author_rank: Frequent Contributor
timestamp: February 21, 2016, 11:45:25 am
content: Thinking I might need to replace the the battery after about 28 years of useI opened up to measure the battery voltage.The voltage on the two diodes is 3.3 Volts, which I consider good after such a long time.BUT, where is the battery?I cannot find it.

author: sync
author_rank: Frequent Contributor
timestamp: February 21, 2016, 12:57:03 pm
content: On a 2246a it's on the backside of the processor board. You have to remove the board to change the battery.

author: AndersJ
author_rank: Frequent Contributor
timestamp: February 22, 2016, 06:47:32 am
content: Found it, thank you.The battery date code is 1988, fantastic quality.
PIC Micro @7.7V didn't died - Page 1
Forum section: electronics / repair

author: ElectricGuy
author_rank: Regular Contributor
timestamp: February 05, 2016, 11:31:45 pm
content: Hi;Just to share with you guys something that i came across today.I received a faulty board from one of my clients. It has been installed and up and running for years. It uses a PIC16F628A. Among other things it has a HeartBeat Led and Uart communications.Everything seems to work fine, only the uart was outputting garbage.After checking the power supply directly to the power pins of the micro, i was measuring 7.7V. It was the 7805 regulator damaged.I replaced the 7805 and the Uart start to work again. Of course i changed the Micro too do to over stress, but is remarkable, since the maximum absolute voltage is 5.5V according to datasheet.Has anyone come across of a something like this?

author: uncle_bob
author_rank: Unknown
timestamp: February 06, 2016, 12:16:44 am
content: HiThere is a *lot* of process variation in terms of absolute upper end voltage. I have seen chips with 5.5V ratings that do indeed blow up at 6V. Most 5.5 V rated stuff will make it to >6.5V in real life.Bob

author: eugenenine
author_rank: Frequent Contributor
timestamp: February 06, 2016, 01:41:12 am
content: Back when they still had a window in the top to UV erase I hooked up one backwards and it emitted light. Switched the power around the right way and it worked fine.

author: poot36
author_rank: Frequent Contributor
timestamp: February 06, 2016, 06:35:45 am
content: I once hooked up a UV EPROM backwards to a homemade arduino based EPROM reader (I tried to get writing to work but didn't) and the bond wire started glowing! I may have also have hit it (and my shift registers) with the 12V programming voltage and it did survive (not so sure about the shift registers though). The EPROM was from a ECG or EEG machine so it should have been medical quality I would think.

author: Gyro
author_rank: Super Contributor
timestamp: February 06, 2016, 10:21:59 am
content: We had an old Prolog briefcase prom programmer (2708/2716 days) that did that if you were careless with orientation. Glowing bond wires is a pretty quick indication!
Binding posts for older HP power supplies - Page 1
Forum section: electronics / repair

author: motocoder
author_rank: Unknown
timestamp: February 05, 2016, 07:04:45 am
content: Has anyone got some HP/Agilent binding posts that they are willing to part with? I am looking for the kind that are commonly found on the old HP 6114A/6115A power supplies, and lots of other old HP equipment. I can get something pretty close to identical from Keysight, but the minimum order makes it not worth it.The attached pic shows the binding posts I am trying to replace. Notice the base is cracked on all 3...
Choosing capacitors - Page 1
Forum section: electronics / repair

author: Vgkid
author_rank: Super Contributor
timestamp: February 04, 2016, 04:53:01 am
content: I'm repairing a power supply that uses several mallory axial caps. 2 of the smaller valued ones I have replaced already. For fun I started looking at replacement options. Radial gives me the most choices, So I will be bodging them in.Current caps are 40v operating at 38v(They cut this really close), and are 85C rated.New caps will be in the 2700uF(or higher) range, @ 105C.2 popular choices in style(good brands will be used).50v @ 5000-10000Hr,63v@2Khrs.Note going for cheap options, using Mouser. Already have a bunch of stuff in the cart.
Samsung Galaxy Note edge - Page 1
Forum section: electronics / repair

author: Fusky
author_rank: Newbie
timestamp: February 04, 2016, 01:22:47 am
content: New here and would like anyone's help, I'm in need to fix a Samsung galaxy note edge. It has a broken glass screen but the digitizer is OK. Now everywhere Ive looked they only sell the screens with the digitizers. This in turns drives up the cost way a lot. Now the person who wants it fixed doesnt want to spend $200 to replace a screen, is there any way to just replace the glass part instead?

author: nanofrog
author_rank: Super Contributor
timestamp: February 04, 2016, 05:58:48 am
content: If you can find the glass without the digitizer, then Yes. That said however, I've not seen the glass by itself, and given it's been out awhile, suspect it will never show up that way due to the fact it's curved (alignment of screen to glass).Should you find the glass by itself however, be aware that you need to apply the adhesive in a vacuum if you mean to do it properly, and that's a not an inconsequential bit of hardware (~$4k for a ready-made solution). It's also predicated on the digitizer isn't damaged when removing it from the original glass shards (additional challenges since it's curved).

author: Fusky
author_rank: Newbie
timestamp: February 04, 2016, 06:10:08 am
content: Quote from: nanofrog on February 04, 2016, 05:58:48 amSo then no , it cant be feasibly done with glass only then. It has to be digitizer and glass then.Thanks for the answer.
Uni-T 61E shows Ohms on Volts, microamp and miliamp ranges? - Page 1
Forum section: electronics / repair

author: alphanumero
author_rank: Newbie
timestamp: February 02, 2016, 09:59:48 pm
content: Recently purchased a UT61E from amazon and was using it today. I love the meter and it was working great. I was measuring the output of a LM317 based power supply, and the meter unexpectedly turned off. I unplugged it from the circuit and switched it back on. The Volt, microamp and miliamp ranges all show ohms in the window. and on the volts range, it's spitting out random values of a few ohms. On the milivolt range, it's reading capacitance. Curiously, the rest of the ranges work fine.Is this a common issue, or does anyone have an idea of what the problem might be? I'd like to just get a new one, since the thing is basically less than one day old. Ironically, I bought this in order to have a nicer, safer meter than my deathtrap of a harbor freight meter.I've tried removing the battery but to no avail, and have checked the fuses. Honestly, not sure what the issue is, and I'm pretty bummed out.

author: Lightages
author_rank: Unknown
timestamp: February 02, 2016, 10:03:41 pm
content: Have you changed the battery? It is probably not the battery. The UT61E is well known to be sensitive to damage from static discharges like from a carpet. It is probably dead, sorry.

author: alphanumero
author_rank: Newbie
timestamp: February 02, 2016, 10:05:36 pm
content: That's what I figured. Thanks anyways.

author: daybyter
author_rank: Frequent Contributor
timestamp: February 02, 2016, 10:14:22 pm
content: Hmmh...something with the rotary switch, that selects the function? Maybe some small piece of metal coursing a short?

author: MrSlack
author_rank: Frequent Contributor
timestamp: February 02, 2016, 10:51:35 pm
content: Replace the battery. They usually come with some cruddy no brand alkaline in it. If that fails, it's probably a warranty job.Got two of them now, the second arriving today, and have had no problems yet.

author: ProBang2
author_rank: Frequent Contributor
timestamp: February 03, 2016, 05:03:24 am
content: Use the warranty.Otherwise look the following video (series) about fixing the same problem:https://youtu.be/GJuvhqfO4Rk

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 03, 2016, 05:21:21 am
content: Quote from: ProBang2 on February 03, 2016, 05:03:24 amSubbed!
Power Supply wont turn on - Page 1
Forum section: electronics / repair

author: synth-dude
author_rank: Contributor
timestamp: January 30, 2016, 05:42:18 am
content: Hi,I pulled a power supply from an old TV, its capable of delivering a few amps supply so thought I could use it as a secondary bench supply.Problem is is doesnt turn on unless it receives a signal to do so, its microcontroller controlled.Just wondering if there is a common way these are activated?Attachment is the board if it helps.Thanks

author: retiredcaps
author_rank: Super Contributor
timestamp: January 30, 2016, 05:50:32 am
content: On the connector to the main board, look for a pin labelled PS_ON. It usually needs to be > 3V in order for the power supply to come on. You can trying tying a 1k ohm resistor between 5V standby to PS_ON.If this is an older plasma TV power supply, you may need more than just PS_ON.

author: synth-dude
author_rank: Contributor
timestamp: January 30, 2016, 09:17:37 am
content: Thanks for the response. Unfortunately I dont have the main board any more. Is there a way to work out which pin it might have been? I could always just try each one with the 5v standby voltage and see what happens.

author: tyguy2
author_rank: Unknown
timestamp: February 03, 2016, 08:03:45 pm
content: That wouldn't be a good idea, you could short something important. I would look up pinouts online.
Marconi 2024 - Unlock - Page 1
Forum section: electronics / repair

author: Andy Watson
author_rank: Super Contributor
timestamp: February 03, 2016, 09:35:32 pm
content: I have acquired a Marconi (IFR/Aeroflex) 2024 signal generator. All appears to be in order except the AM modulation depth - it appears to reach full modulation at approximately 92%. Does anybody know how to unlock the "Level 2" calibration functions without the 6 digit key? (Level 1 unlocks with the default 1234, but the level 2 code has been changed.)Thanks.
sometimes I'm lucky and I found a scope! - Page 1
Forum section: electronics / repair

author: vaualbus
author_rank: Frequent Contributor
timestamp: January 20, 2016, 10:24:02 pm
content: So sometimes I'm lucky!Last friday I menage to find in the garbage of my university an oscilloscope! I menage to find the the lecroy wavesurfer 454 and now I take it home. (Luckly my mum work at my univesity so it ask to the guy that apparently "menage" the garbage and he let him to take the scope at home)!!!But of course it not work. There was a label on it that tell two problems: Power supply and vertical amp.I menage to dissasenbled and I arleady found a bad ic on the psu.The big problem is that on the net there is no service info on the scope!Any way something is better than nothing!Good luck guys!

author: daybyter
author_rank: Frequent Contributor
timestamp: January 20, 2016, 10:46:47 pm
content: Congrats!Start a repair thread in this forum? With some pictures etc?

author: vaualbus
author_rank: Frequent Contributor
timestamp: January 20, 2016, 11:01:45 pm
content: Ya i will do that tomorrow.

author: uncle_bob
author_rank: Unknown
timestamp: February 03, 2016, 02:15:37 am
content: HiIF there is enough of the markings left on the IC, get a good picture of them. If there are no markings left, at least get a shot of the package and the parts around it. Anything you can do to trace the general circuit it's it is likely to help identify it.Bob
Help Identify SMD Resistors - Page 1
Forum section: electronics / repair

author: NivagSwerdna
author_rank: Super Contributor
timestamp: January 31, 2016, 12:50:31 pm
content: Please can you help me identify the components in the images. I believe they form part of a current sense circuit. These are pictures of working devices, the ones I need to change are blackened from having been on a high current path.

author: Fank1
author_rank: Regular Contributor
timestamp: January 31, 2016, 12:54:33 pm
content: The first photo shows a 22uf 35v tantalum capacitor.The other a 2.2 ohm resistor.

author: AF6LJ
author_rank: Unknown
timestamp: January 31, 2016, 01:07:29 pm
content: Fank1 Beat me to it.Good catch.

author: station240
author_rank: Unknown
timestamp: January 31, 2016, 05:44:21 pm
content: Guide on identifying the package code used, you'll need a ruler.http://www.resistorguide.com/resistor-sizes-and-packages/

author: NivagSwerdna
author_rank: Super Contributor
timestamp: January 31, 2016, 06:00:50 pm
content: Quote from: Fank1 on January 31, 2016, 12:54:33 pmThank you very much.#1226 being 22x10^6 picofarads?35 being 35V.What does the K or the 107 represent?#2Ah.... OK 2R2... = 2.2OhmsI assume Dale is the manufacturerWhat does the 0046 represent?Thanks again

author: PTR_1275
author_rank: Frequent Contributor
timestamp: January 31, 2016, 11:49:57 pm
content: For the capacitor, K would be the tolerance.J is +/- 5%K is +/- 10%M is +/- 20%I imagine the other numbers on both will be manufacturer codes, batch, date of manufacture or something like that and yes, sale would be the manufacturer of that resistor.In low value resistors the substitute the decimal place with R so it is harder to miss. If it said 2.2 but the . Didn't print, or you didn't look close enough you would think it is 22 ohm (or possibly 2 with a multiplier of 2 zeros). The R is a lot harder to miss.Some of the shunt resistors on the gear I work with are marked R001 (1 milliohm)Hope this helps.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 02, 2016, 10:20:49 pm
content: Could #2 actually be an inductor? 2.2uH ?(If so the subject name is a bit misleading)
EEPROM bluetooth 4.0 USB CSR 4.0 - Page 1
Forum section: electronics / repair

author: warmaq
author_rank: Newbie
timestamp: February 01, 2016, 08:52:28 pm
content: HelloI need dump of eeprom of USB bluetooth CSR 4.0, becouse i damage it with program PSTool.EEPROM chip - k24c32I attached PCB foto.RegardsWarmaq
Safely replace FCC connector on TFT screen module? - Page 1
Forum section: electronics / repair

author: e-pirate
author_rank: Regular Contributor
timestamp: January 31, 2016, 03:13:49 pm
content: Hi, folks.I wonder how to safely desolder 40 pin FFC connector from TFT screen module I have. I'm afraid of damaging the TFT matrix underneath the board while heating the connector with hot air station.Any suggestions here?

author: e-pirate
author_rank: Regular Contributor
timestamp: January 31, 2016, 04:41:42 pm
content: Well, actually it wasn't so hard. I spent more time think on how to desolder it, then actually desoldering it. I cut two holding pins on the side with a paper knife and forced them out with soldering iron. Then solder blob technique did quite well in that particular case. Especially after realising that I can sacrifice the connector and brake it. But, unfortunately, I lost the replacement connector. It is simply disappeared into thin air
Vizio 60" Smart TV Repair - Page 1
Forum section: electronics / repair

author: adept
author_rank: Regular Contributor
timestamp: February 01, 2016, 12:37:24 am
content: Hi,I took apart my TV because the screen went dark. The backlight still comes on but there is no picture.This is a 2013 model, not the recalled 2012 unitI checked the voltages. They're normal when the TV is off but when it turns on, both dip to a couple of millivolts.The capacitors have no visible sign of damage (i.e. pin holes in the top or bulged tops)The capacitance measured on the input and output of the regulators both exceeds the abilities of my meter.What should I do? Do I give up?

author: JoeO
author_rank: Frequent Contributor
timestamp: February 01, 2016, 02:40:54 am
content: What model number is it??

author: adept
author_rank: Regular Contributor
timestamp: February 01, 2016, 03:06:31 am
content: It's a E601i-a3e. I tested the T-Con board according to an online testing tutorial. The MOSFET driver for the panel has a short from drain to source, is not acting like a diode, and I'm getting 0V on all the pins on this MOSFET. This could mean the panel is bad, but I didn't have problems with the panel before. Anyways, looks like a $70 gamble to get the T-Con board and I don't know if it will be worth it. What do you guys think?

author: Bryan
author_rank: Frequent Contributor
timestamp: February 01, 2016, 06:58:48 am
content: Maybe this helps

author: Srbel
author_rank: Frequent Contributor
timestamp: February 01, 2016, 11:07:13 am
content: Replace the MOSFET and see if it works. Or just unsolder it, and see if the short is gone.
Asus h81t Motherboard shocking me - Page 1
Forum section: electronics / repair

author: PowerRepo
author_rank: Newbie
timestamp: January 30, 2016, 02:27:06 am
content: Hi everybody i have a h81t asus mini itx motherboard and ahttp://www.mini-box.com/19v-8-4A-160-Watt-AC-DC-Power-Adapterpower supply for some reason if i touch ground it shocks me this power supply is wired for +19volts on the inner ring and -19volts on the outer rinf and nc not connected on the center pin i think this is where the priblem is that its sending 19 volts to ground can someone help thanks

author: Rasz
author_rank: Super Contributor
timestamp: January 30, 2016, 09:55:07 am
content: no, the problem is buying chinese crap and bad wiring in your house. im guessing its not isolated and there is potential between its ground and AC in the wall

author: Tim F
author_rank: Regular Contributor
timestamp: January 30, 2016, 10:55:23 am
content: Quote from: PowerRepo on January 30, 2016, 02:27:06 amWhat are you measuring these voltages in reference to? I.e. when you 'measure 19V on ground' what are you probing with the other multimeter lead?If you mean that your meter reads +19V when you put the positive probe on the inside ring and the negative probe on the inside ring, and then -19V when you reverse the leads then this is normal. The multimeter doesn't know what is supposed to be ground, that's why you have to connect the negative/ground probe to something to give it a reference. If you connect the leads backwards then the measured voltage will be negative as now the multimeter is using the '+19V' as it's ground reference, and the powersupplies ground looks like -19V compared to it. +/-19V DC isn't really enough to give you a shock on dry skin anyway.What you need to do is to put your multimeter on AC voltage and connect one lead to real earth (e.g. the earth on a mains outlet, or a metal building water pipe) and the other to powersupply output ground. You should see no more than 30V AC. If you see more than that then there is probably enough leakage between the primary/mains of the powersupply and the output to give you a mild shock. Either that or the electrical wiring in your building is not earthed correctly.
Help identifying a chip - Page 1
Forum section: electronics / repair

author: synth-dude
author_rank: Contributor
timestamp: January 29, 2016, 11:01:40 am
content: Hi,I have this chip pulled from a HP printer, has the codes on it but nothing turns up online, anyone know what it might be?My first guess would be a 186 microcontroller but not sure as nothing turns up.Cheers

author: amyk
author_rank: Super Contributor
timestamp: January 29, 2016, 12:34:19 pm
content: Some variant of Fujitsu 4-bit mask ROM microcontroller, MB88 series.
Faulty Hall Lid sensor laptop - Page 1
Forum section: electronics / repair

author: Sublime89
author_rank: Newbie
timestamp: January 29, 2016, 01:03:32 am
content: My gateway nv53 laptop screen will not turn on.i think it is the hall sensor because I had a problem in the past where I had to press on the lcd screen where the magnet is to get the screen to turn on.The screen will not come on at all anymore so I think the hall sensor finally failed.I saw another thread on this forum where a guy removed his hall sensor from motherboard and it fixed the problem but I'm not sure how to do that.supposely I would need to jump the connection so screen is always on.Here is the thread about that.https://www.eevblog.com/forum/chat/defective-hall-sensor/Here is a screenshot of my board with the hall sensor I need to remove.not my pics thoughhttp://www.3designstudios.com/lidswitch/lid-switch-2.jpghttp://www.3designstudios.com/lidswitch/lid-switch-1.jpg

author: wraper
author_rank: Unknown
timestamp: January 29, 2016, 01:22:10 am
content: I really doubt it is a hall sensor. Does it work with external display?

author: wraper
author_rank: Unknown
timestamp: January 29, 2016, 01:28:09 am
content: QuoteIt's more like you had a problem with the LCD panel or the cable/connector/ccfl inverter (if it's an old laptop) which you were pressing. How pressing the magnet can bring the display to life in any reasonable way, especially in the position in which the hall sensor does not sense it at all? Magnet is only for switching the display off, when the lid is open, hall sensor does not care is there is a magnet at all.

author: Sublime89
author_rank: Newbie
timestamp: January 29, 2016, 01:43:55 am
content: No it doesn't work with external. I looked up before months ago when I first had the issue and someone with the same computer on another forum said if you press on the bottom left screen where the magnet that controls hall switch(maybe not hall switch) is located it will turn the screen on but this wont work anymore so I always figured it was the magnetic lid switch failing.i wasnt pressing on any wires I was pressing on magnet when it turned the screen on.several other people said by pressing the magnetic part turned there gateway screen on another forum.Last time the computer was running it froze and I couldn't use mouse pad or keyboard and was forced to shut down with power button.the computer was really hot too. Is this possible a sign of failed graphic chip if not lid switch.

author: wraper
author_rank: Unknown
timestamp: January 29, 2016, 02:14:30 am
content: QuoteYes it is. In your case the lid switch is very unlikely to be the cause of the fault. Are there any signs of the laptop actually booting? Like HDD led showing activity.

author: Rasz
author_rank: Super Contributor
timestamp: January 29, 2016, 04:53:12 am
content: pressing on magnettons of people with same problemhttp://www.tomshardware.co.uk/forum/id-1736826/gateway-nv53-showing-display-powered.htmlof course one village idiot "pc tech" suggests cooking laptops wrapped in rags to magically fix faulty gpu ...this one makes most sense:Quoteseems something is shorting near hinge mechanism?
Power supply K-3206 - Page 1
Forum section: electronics / repair

author: mgf897
author_rank: Newbie
timestamp: August 05, 2015, 10:59:59 pm
content: Does anyone have a copy of the schematics for a K-3206 40V/3A power supply?I recently bought one used of eBay and would like to check it over. I believe the power supply was originally sold as a kit. Thanks.

author: tautech
author_rank: Super Contributor
timestamp: August 06, 2015, 01:10:21 pm
content: Brand?Photo, as it might be a re-brand.

author: mgf897
author_rank: Newbie
timestamp: August 07, 2015, 03:13:38 am
content: Hi Tautech, it's a dick Smith model. I'll post a picture when I get home.

author: aargee
author_rank: Frequent Contributor
timestamp: August 07, 2015, 06:29:09 am
content: It was an Electronics Australia design (Dec '93 / Jan '94). Silicon Chip magazine will have back issue copies.

author: Unknown
author_rank: Unknown
timestamp: August 07, 2015, 07:08:53 am
content: K3206.zip. EnjoyIthinkit includes the very important errata about the transformer secondary connections - the original overlay / connection diagram had, IIRC, the CT & one side reversed. (From memory it took 12 months or more for EA to post that errata!)As a general tip: it also benefits from added decoupling, etc. otherwise it's a bit prone to ring/oscillate. I've got a link or list somewhere somewhere which mentions a few mods; I'll try and dig it up post it later.edit: Thinking back on it, the original overlay / diagram might've had one half of the secondaryshortedto the CT/gnd (the schematic was correct). No errata mentioned in my PDF, so you'll have to trace it out yourself (it's pretty obvious). Needless to say, don't power it up without checking that out.Also, the DSE kit supplied a slightly under-spec'd E-core transformer rather than the specified toroid - end result was it had trouble reaching 40v or, if it could, it couldn't supply much current.Andhere's the thread on EDAboardwhere they discuss anti-oscillation fixes/mods.

author: mgf897
author_rank: Newbie
timestamp: August 07, 2015, 11:08:51 am
content: Awesome, thanks tac eth xilef

author: Webserfer
author_rank: Newbie
timestamp: January 30, 2016, 03:39:28 am
content: I know this is over 4 months later but I just got lucky on ebay and got a brand new unopened kit for the power supply if you still need any docs that may of came with it. Was fun to unbox I'll say

author: VK5RC
author_rank: Unknown
timestamp: January 30, 2016, 11:40:56 am
content: Now that little puppy served me well for probably the best part of two decades as a quick little power supply, still have it. The only issue I had was it does over heat a bit if you start pushing it on a hot day (and its thermal cut out I set a bit low) and its start up voltage curves aren't fantastic but a great little unit for starters.The usability of analogue type PSUs are pretty good.
[Answered] Can anyone help me figure out who the manufacturer of this opto is? - Page 1
Forum section: electronics / repair

author: AmirTheGreat
author_rank: Unknown
timestamp: January 26, 2016, 01:12:58 pm
content: I need to replace this guy and trying to find this part (or equivalent) and not having much luck.Anyone recognize the logo?

author: wraper
author_rank: Unknown
timestamp: January 26, 2016, 01:20:15 pm
content: LiteonIt's LTV-817S-AIt's one of the most common optocoupler types. better to search for PC817 as this what they are usually called by most of the manufacturers.

author: AmirTheGreat
author_rank: Unknown
timestamp: January 26, 2016, 01:35:42 pm
content: Quote from: wraper on January 26, 2016, 01:20:15 pmYou are a saint!
HP6626 Fan "Upgrade" - Page 1
Forum section: electronics / repair

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: January 26, 2016, 10:13:06 am
content: after playing with my HP6626 toy as "bench supply" for several weeks now, i must say that this is a darn fine piece of equipment that you will have to pry from my cold dead hands.one thing though that annoyed me straight from the beginning was the extremely noisy fan, so that guy had to leave the building asap. i exchanged it with a 12VDC bequiet! "shadow wings" fan that has about 70% of the airflow of the original one. that amount of airflow seems ok to me, as i'm not going to use the HP6626 anywhere beyond 30°C ambient.the supply for the fan is a 12V LED power supply (constant voltage variety) with 110VAC input. in order to prevent any switching noise from radiating into unit, i wrapped the supply in self-adhesive copper foil and tucked it away in the compartment behind the front panel. i also bodged together a linear temp control with a TMP35 as a sensor placed into the airflow right at the exhaust ports of the HP6626.now, the "primary" noise from the unit is just the mild hum from the transformer, hence making it the most silent piece of equipment in my lab besides the soldering station.(OT: if anybody needs a good working original fan: send me an offer)FYI, as a side note: being paranoid of old ROMs dying , i managed to read the contents from the power pcb's MC68705R3 processor (5080-2128) and verified the data with a freshly programmed µP in the HP6626
Sun  2055 TVC  24" display . Help needed for power supply fix.  - Page 1
Forum section: electronics / repair

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: January 23, 2016, 01:58:19 pm
content: Dear All,I am trying to fix this 24" Sun 2055 TVC display.Contrary to some previous ones, I do not see some obvious bad capacitors.I have replaced one, which did not look particularly bad, but there is still some problem :There is a large (2.5 V amplitude ) 1 second period signal in the 19 V output.Can anybody provide me with some hint of where to search in this PSU to fix it ?

author: JacobPilsen
author_rank: Regular Contributor
timestamp: January 23, 2016, 08:59:46 pm
content: Did you measure any of that not-so-obvious capacitors?(i.e. green between heatsinks)

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: January 23, 2016, 10:54:17 pm
content: I have measure the green ones.They were OK.I have still replace them with new (larger ones 2200 uF like the Brown one close )but it is roughly the same thing.The 5 V and 5.3 V are OK ( in the lower part of the board). The big central cap is OK.So I suspect that it is not a capacitor, but need to confess my absence of expertise in this matter.This is why I ask for help.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: January 24, 2016, 07:34:58 pm
content: If this can help, I have identified the board.It is a FSP100-3P01

author: EPTech
author_rank: Regular Contributor
timestamp: January 24, 2016, 08:47:13 pm
content: Hi There,If your are getting the 5V correct, that means that your standby supply on the bottom is working. The main supply seems to be unable to close the loop and is constantly trying to restart. Sometimes you can hear this: it ticks at the same rate as the waveform you are seeing on the scope.The most obvious cause is a low impedance on the output. Disconnect the supply and measure the output impedance using a simple DMM. A bad output CAP may cause this.Is there SMD on the bottom, maybe a PWM regulator (494). It looks like there is an auxiliary supply on the primary of the main transformer. If so check whether the supply for the PWM (494) controller is working correctly, usually around 12VDC. May also be on of the little caps on that is bad.Be careful measuring on the primary side with the scope. Use an isolation transformer.
LF service manual - Page 1
Forum section: electronics / repair

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: January 24, 2016, 02:50:32 am
content: Just found a 1987 vintage NEC PM-917A 9" color monitor. I couldn't find a service manual; Googled deep, checked with NEC, eBay, Yahoo groups, nothing...Any leads?The monitor works so far, it's not a terribly complex beast, but I'd sure like a manual!

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: January 24, 2016, 05:14:56 am
content: This site has some manuals for some old CRT monitors, but I noticed there are several which are referenced by a series number, part number, etc. Maybe there is other info on the tv which you could use to locate the manual's title.http://www.nec.owner-manuals.com/NEC-manuals-1-20a.html?alpha_filter_id=80
LeCroy 454 Repair - Page 1
Forum section: electronics / repair

author: vaualbus
author_rank: Frequent Contributor
timestamp: January 23, 2016, 07:36:17 pm
content: I all, so after I find the schematics and the service manual, I begin to troubleshooting the unit. I find a bad mosfet the 2sk3148 and I replaced it with the irf540. Unfortunally that is not the problem.Here the situation:If I connect the unit width the 220V both fuses breaks, so something is bad on the primary side or on the pfc board.Than I come out with the idea of power the unit with the external dc in, so I bought a 19V 5A psu and connect it to both CN9 and CN10. (The stand by voltage is generated from the main ac so without it I never get the stand by voltage).And than the problem start:- If I connect all the cable to the analog board and to the motherboard, the unit turn on for a while and than turn off.- If I only connect the motherboard I can't get the motherboard to start But the motherboard is good, I try it with an external psu, and it boot.- If I connect only the analog board the psu automaticly turn on and all the voltages are ok.- If I mesaure the -12v rail when all the cable are disconnected it measure only -3.5v, but it become ok when I connect the analog board to the power supply.Now I'm wondering what can be wrong in psu? Any ideas?Also anyone have an idea where to find the restore program because the unit miss the hard disk so I need to insert a new one and reinstall all the software.In the service manual it is rittent that you need the "WS400 Series Control Program" cd/dvd, and the "Startup Disk for WS400 Series Control Program" floppy disk.Where to find an image of it?Best regards, Alberto.

author: JacobPilsen
author_rank: Regular Contributor
timestamp: January 23, 2016, 08:31:46 pm
content: Elektroda.pl/ topic3037254ONSemi.com/ MC34262

author: vaualbus
author_rank: Frequent Contributor
timestamp: January 23, 2016, 10:30:57 pm
content: So I take a look at the Pfc board and found a bad mosfet and bad diode.Anyway that not solve the issue I'm looking.I really think that there has to be a problem on the -12v rail. Is so strange that is only -3.7V unloaded and go to -12v when all the board are connected.
Dell Latitude E6410 lines on screen. - Page 1
Forum section: electronics / repair

author: ResR
author_rank: Regular Contributor
timestamp: January 22, 2016, 07:21:53 pm
content: One moment every second row of pixels from 10th row from the top turned grey on the LCD screen with this odd color swamping from top to bottom and first line flickers. One of the guess is that the video chip between the processor and display is dead, cause the VGA output worked well. Any ideas what would be the cause?

author: kripton2035
author_rank: Super Contributor
timestamp: January 22, 2016, 08:14:26 pm
content: reflow the bga video chip for all laptops from any manufacturers that are 3+ years old is most of the time the solution to this kind of problema simple reflow will fix it for at best one yeara complete reball will fix it for more time.

author: Rasz
author_rank: Super Contributor
timestamp: January 23, 2016, 02:21:53 am
content: NVIDIA NVS 3100M = beyond economical repariQuote from: kripton2035 on January 22, 2016, 08:14:26 pmbullshitreflow will fix it until the first time user actually uses GPU (runs a game/program loading gpu)reball will be the same, because defect is IN THE GPU

author: kripton2035
author_rank: Super Contributor
timestamp: January 23, 2016, 08:22:51 am
content: I said "most of the time" ...I've fixed dozens of laptops this way (but not that particular model)

author: crispy_tofu
author_rank: Super Contributor
timestamp: January 23, 2016, 11:05:28 am
content: Quote from: Rasz on January 23, 2016, 02:21:53 am+1Good video on this:

author: amyk
author_rank: Super Contributor
timestamp: January 23, 2016, 03:51:17 pm
content: Those symptoms don't seem like GPU/VRAM to me, especially if the VGA output still works. It could be the screen or the LVDS cabling.

author: Robomeds
author_rank: Frequent Contributor
timestamp: January 23, 2016, 07:51:26 pm
content: Without knowing the subtype, not all E6410s used NVIDIA chips. I suspect the majority had Intel GPUs. This sort of failure looks more like a display vs GPU failure to me. Perhaps the easiest fix is just to find a similar system on ebay and swap parts. I'm not sure which screens were offered on that model, probably just one or two resolutions. At the time only the 15" models had lots of choices. Anyway, my guess would be a failed connection but I would also suspect it won't be easy to fix. This is not a well educated guess but I have spent some time working on the somewhat related E6500 systems and the earlier Latitudes.