DELL Nvidia GTX 750Ti Mosfet goes short after a few minutes

[aaronkatrini]

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 card back on the motherboard, runs fine for a few minutes then shuts off again - Mosfets again shorted.

What could be the issue? Fauly mosfet driver?
Any suggestions would be gladly appreciated. Thanks in advance.

[DynaxSC]

Hi, can be any part in the VRM network, a degraded silicon in a driver or vrm controller, a cap at the edge of failing or dryied out, especially electrolytic cap, a resistor which is decalibrated, especially low value resistors, a cold solder point. It will be difficult to diagnose, I'd start with exchanging all the electrolytic caps in the vrm net and checking the low ohm resistors. Also the stability of the vrm controller / driver power supply can be important. Only way is to exchange succesively all parts. Check also the 12V cables and 12V ATX socket if present, might be that the contacts are oxidated, same with the pcie contacts for power supply. Finally it can also be degraded gpu silicon shorting when getting hotter.