Hello, I would like to present a huge post but I am not very good with this so I will go straight.... First of all, I am from Cuba and the problems that might seem small here are enormous.... I have gotten an Amd R9 270 (which is an AMD edition, not Asus, not MSI) I got it super cheap... it initially did not show video signals... so I disassembled it to see if I could repair it using my own method (big mistake) Well anyway... I identified 1 MOSFET as short so I changed it... then I did some measurement tests and absolutely everything within the green zone marked me as short, both the caps and the coils... and That obviously can't be... I measured the other MOSFETs to find out if any others were damaged but I didn't find any more... and I didn't know what to do... I hope to get some answer.... Without further ado, Greetings colleagues...
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remove all mosfets and check for short. or use miliohmmeter to check for shorted mosfetComment
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Thanks For Reply...I already did that and I still get shorts in the vrm area... I'll measure with milliohms to see if I have another result... now the main problem is that I don't have a way to replace a MOSFET that was in short... I don't have access or way to acquire new...Comment
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Hi all,
I have recently picked up this Dell OEM Nvidia GTX 750Ti 2GB Video card. Its an old card I know but still wanted to get it working if possible. The problem is the following:
- Put the card in my testing motherboard and start running Heaven benchmark
- Benchmarks seems to run smoothly up until half way then the motherboard completely shuts off immediately
- Try to start it again and I get a slight move from the PSU fan - a clear short
- A little troubleshooting later I find one shorted Mosfet - Replace them both - short is gone
- Put the... -
Hi,
My laptop went dead and after checking ,the main 19 volt power rail was shorted. After some checks i could identify that a high side vcore mosfet was shorted.
I replaced the mosfet and now the white powerled is present , fans start spinning but capslock shows the famous 5 long and 3 short code.
I checked the vcore voltages after replacement and i get for all 1.01 V so means for me that the driver is still working of the replaced shorted mosfet. On the Nvidia i measure around 0.8 V after the mosfets.
I did voltage injection on the cpu with 0.7V and i have a current... -
Hi all.
This notebook was showing no signs of life.
I removed the FH52M LA-J891P mainboard and found that there was 19V at the DC jack.
However there was zero volts on the two PRB2 and PRB46 resistors immediately after the two polarity protection MOSFETs (PQB11 & PQB12).
If I remove the PQW1 MOSFET, the 19V rail starts working, and I can turn on the unit - at least I get the fans, and the power light comes on, when I simulate the power button being pressed. No display.
I tried replacing the MOSFET with a new one, but again no voltage on the... -
I got this laptop from friend with problem short 19v....when i check this 2 mosfet getting short...i remove that mosfet and confirm that mosfet is short...
and check that 2 capacitor PC9009 and PC9004 pad is also short...already check where that capacitor goes and came from but cannot find the main problem...please help
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Looking for guidance in tracking down missing main power rail.
I have an Acer that I am working on. It runs on the battery, but does not charge. I changed the power adapter and same thing battey not charging, and continues to discharge. So I opened the computer and started looking for the problem to fix.
First thing I checked is if the power form the charger is getting to the mainboard. I found that 19V is going all the way to the first MOSFET. So DC jack is fine. However I do not have power past the first MOSFET.
So checked for voltage on the gate of the first MOSFET and...
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