Gigabyte GA-H61M-USB3-B3 dead short 3.3v rail to ground.

[JimMc0]

Hi there,

I discovered this forum through a youtuber who teaches electronic repair. I've been trying to troubleshoot my dad's old PC which is a Gigabyte GA-H61M-USB3-B3 and will not power on. I discovered a dead short on the 3.3v rail at the ATX connector so I used a bench power supply to feed 3.3v into the ATX connector and sunk about 400mA into the board (I hope that's not too much!). I used a FLIR camera to identify the problem area:



The chip seems to be the following, an ITE IT8892E 1108-CXS which seems to be a PCI bridge?



I started measuring the components surrounding the chip and with the DMM in the audible resistance mode, I was getting a bleep on the components circled in yellow in the above photo, however, when I put the DMM into ohms I was reading 0.6 Ohms on all three components, so I wonder if perhaps the chip has failed and that's giving a spurious reading? I don't actually use any PCI cards on this board, so I was left wondering if I could just desolder the chip altogether and whether the board might run?

Failing that any further troubleshooting advice would be appreciated.

BR,

Jim

[JimMc0]

I went ahead and removed the chip from the board and thats cleared the short, I'm now reading approximately 270 Ohms from the ATX connector on the 3.3v rail. Unfortunately in the process of removing the chip I've damaged the pads on the board, and the board will not start without the chip (assuming that was the only fault), so I think thats essentially rendered the board
dead at this point.

Those three components highlighted in yellow continue to measure 0.6 Ohm after removing the chip, by the way.