Re: Samsung - LE46C750R2K - BN44-00341A PSU - No Power
Sorry. I can not currently measure it, cause I only have the power PCB with me. I will write the measurings as soon as I can.
CroTech
Student
Last Activity: 07-24-2024, 10:55 AM
Joined: 12-26-2012
Location: Zagreb
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Re: Samsung - LE46C750R2K - BN44-00341A PSU - No Power
Hi,
OCF did you manage to diagnose what was wrong with the board, I got the same TV and experiencing same symptoms.
ThanksLeave a comment:
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Re: Sapphire HD 7870 possible short
[URL="https://www.youtube.com/watch?v=wEwKkhxI73M"]Yeah thought so,
when watched this video[/URL]Re: Sapphire HD 7870 possible short
[URL="https://www.youtube.com/watch?v=wEwKkhxI73M"]Yeah thought so,
when watched this video[/URL]Leave a comment:
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Re: Sapphire HD 7870 possible short
Aaaaaand removed all of them, SOURCE AND DRAIN still shorted...Leave a comment:
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Re: Sapphire HD 7870 possible short
UPDATE:
Took one IC off a board and tested it and it checks out fine.
Checked for shorts on the PCB where the pads where, YUP all three SOURCE short to DRAIN.
Sorry for low quality photo.
Could it be that if one of the VRMs is making a short between SOURCE and DRAIN that they all get shorted?
I wonder what would happen if I took them all down....Last edited by CroTech; 02-12-2018, 09:26 AM.Leave a comment:
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Re: Sapphire HD 7870 possible short
Back with more info.
Found out that you can measure Vcore on the middle SMD capacitor on the back of the gpu, while PC was on, and everything connected I got 0.02V so that is saying the core is not getting the voltage.
Also started looking the VRMs, I have [URL="http://www.onsemi.com/pub/Collateral/NTMFS4983NF-D.PDF"]4983NF[/URL]
Tried this [URL="https://www.youtube.com/watch?v=gloikp9t2dA"]method[/URL]
Diode mode beeps on DRAIN TO SOURCE no matter which probe is on...Leave a comment:
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Re: Sapphire HD 7870 possible short
I have to check where should I measure those voltages since I havent done this before but I will have it a go. I really doubt it is a BGA problem since the card worked flawlesly in my main rig but I upgraded to gtx 1070. My main fault was putting a molex converter to 6 pin since the old PSU had only 1 6pin power connector and even on first boot GPU was working fine but when I streesed the gpu with a game then it died.Leave a comment:
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Re: Sapphire HD 7870 possible short
Yeah. Tried both DVIs and the HDMI. Dont have a display port device so... But the card is not shown in the device manager. Are there any more fuses on the card I should check? Thanks for the reply Momaka.Leave a comment:
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Re: Sapphire HD 7870 possible short
SO for the fuses, the only 2 I found are those by the HDMI connector and they are probably there for protecting the HDMI device, they checked out fine on the multimeter, in diode mode it beeps, in resistance mode they are short....Leave a comment:
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Re: Sapphire HD 7870 possible short
Momaka, you were right, after leaving it for a 2-3 min the caps charged and the measurements are different, here are the photos, the same thing applies to the second connector.
So I am looking for a blown fuse/component that is connected to the second pin on each power connector? Since the resistance is infinity on those.
I did not upload the second connector photos since they are exactly the same....Leave a comment:
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Re: Sapphire HD 7870 possible short
With the video card plugged in the PCIe, and both connector from the PSU to the Video card the PC turns on, works well on the integrated GPU and it boots normaly even thoguh Ohm meter shows 1 Ohm on the marked terminals.
The GPU did not have any problems so far with the BGA and has not been "oven repaired".
Also I would like to add that while the PC is on, the heatsink is cold and the GPU is not developing any heat.
So I would say that the GPU chip is not shorted, however I do not understand how...Leave a comment:
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Re: Sapphire HD 7870 possible short
Hi guys,
So my XFX R9 380 was working fine but I wanted to put it to my cheaper/weaker PC since I got upgraded, everything was working fine, but I think my generic PSU killed it somehow.
I installed the GPU and it turned on ok, started playing a game and suddenly black screen.
I restarted PC but the GPU seems to be as if not pluged in.
Took the heatsink if and saw the connector terminals are shorted, spotted these 2 MOSFETs shorted and replaced them with indentical, nothing changed....Leave a comment:
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LG flatron-w2361v reset
Hi all, I found LG Flatron W2453V at the dumpster, it had a white screen only, so I noticed a burned out SMD coil on the digital board and since it can not be replaced, I bought cheap board with controls, but this one was from LG flatron w2361v.
The problem is that now, I have kind of a demo that shows half of the screen in one settings and the other different, it can be seen in the pictures.
I am wondering is there a way to reset digital board eeprom or the board itself since my controls on the monitor are not working, only the on/off switch works (so, no menu, no nothing)....Last edited by CroTech; 07-24-2017, 06:44 AM. -
Re: Vestel 17ips11
ReeceyBurger, I presume you had the same problem? Cause I was reading about how dead LEDs and blinking LEDs can kill the power supply board....Leave a comment:
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Re: Vestel 17ips11
Got the PCB to a frend of mine who repairs TVs and he told me that both of the SMD ICs on the back of the PCB (green side) seem to have wrong readings and that they should be replaced, so I am gone order new ones and ones I replace them I am going to make a new post.
Thanks guysLeave a comment:
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Re: Dell 2209W - no power at all - stripped down but can't see anything obvious
Have this one laying for some time now... The first thing when I opened it I noticed that it has the same PCB as the one in this thread.
The board looked OK except the LD7575 was severly burned so I unsolder it and cleaned the PCB with alcohol, bought 5 replacement LD7575 ICs and soldered a new one.
Put it to the test and voila, had smoe sparks and grey/whiteish smoke coming out of it.
All the fuses seem to be OK, the capacitors seem to be okay, but the LD7575 suffered...Leave a comment:
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Re: Vestel 17ips11
I know, but having it stressed for half a second I dont think it damages it cause I have seen them shine even brighter through original power supply, that is actually how TV manufacturers make sure it fails after the warranty is out
plus it is a old battery that is half way drained, that is why when you connect it to 3 LEDs in series they shine poorly.
As soon as I get my hands on TV again I will measure CN100 pin5Leave a comment:
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Re: Vestel 17ips11
Sorry I did not check but I will as soon as I get some free time...
Let me explain my "checking LED method" since it is simple, fast and bulletproof.
I take a 9V battery and solder a wire to a + and a wire to -
Now I solder + wire to a sewing needle, and - wire to a another sewing needle. Why sewing needle? Cause they are conductors and they can easily punctre the LED strip isolator. Now when the "TESTING DEVICE" is ready I take one end and try to pin the LED, once I see bright light from...Leave a comment:
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Re: Vestel 17ips11
The stripes are fine. I replaced the bad LEDs with new ones and tested it with 9v battery and 2 needles and every one of those shines bright light... The voltage without LEDs connected are the same and drop to zero. So it seems that fail protection turns on even though LEDs are not connected.Leave a comment:
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Vestel 17ips11
So as the title says... I have got the most F-ed up power supply that I need to somehow repair since it is either impossible to get it in Croatia or too expensive.
First things first, it is a 32" Quadro LED LCD TV which all of a sudden did not wont to turn on, no backlight but there was some picture that could be seen in a dark room and the sound was OK.
Opened it up, tested the LED strips and there were 6 dead LEDs, replaced them put everything back up, nothing changed. Measured the output on the power supply and it gives 42 V on DC range and 96,4 V on AC that goes...Last edited by CroTech; 01-05-2017, 12:38 PM.
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