Seller Note “Was given to me by a friend and has been laying around in a draw safely for a while now has not been tested and don’t know if it is still working. have no way of testing it either” – sounds like a typical Ebay seller fake cover story… why did I buy this…
Summary
- This card has a 12v short on the PCI (of course a friend gave it to them, nice gift of a card that is clearly broken!)
- Sadly, I strongly suspect that the 12v reached the core after injecting 1v.
- I have located the shorted VRAM DRMOS (U4536) using an ESR meter. This inductor showed less than 0.9 Ohm, all others 1.04 Ohms. This DRMOS is also featuring a solder bubble.
- There is another problem, fuse F1 seems somewhat vapourised!
- Overall, due to that short, I would fully expect this card to be spare parts, as the core probably saw 12v at some point. However, I will still go-ahead to try and resolve the short, assuming the DRMOS can be easily removed.
Used a preheater and 450 degrees C hot air and the DRMOS came off nice and easy.
Amazing! Not sure how, but I have normal voltages and a BIOS picture! 🙂
That DRMOS is http://www.sinopowersemi.com/temp/SM7320ESQG_datasheet.pdf
Now there’s a chance this is fixable, I should next
- Check the VRM is stable (oscilloscope)
- Replace the cooler and check if I can get to windows and load drivers (GPU might still be compromised)
- Check readings to see if the PWM and driver resistances for that phase seem normal
- Find that fuse
- order parts