G5 Quad doesn't POST with card in PCIe slot one...

[MisterKeeks]

Have a G5 quad with an obviously failing LCS. Weird thing is, it doesn't POST if you have any card in PCIe slot 1. I have tried a 6600LE, 7800GT, and an x4 Fibre Channel card. If anything is in the slot one, no chime, nothing on display, etc.

Have tried reseating, etc to no avail... Why might this be and any fixes?

 

[AphoticD]

It could be a short circuit. I would examine the slot with a magnifying glass, torch and some tweezers. Inspect the solder of the slot on the board (front and back) for any signs of corrosion. Clean the solder and slot with IPA and a toothbrush.

I had the same issue with a Dual 1.8Ghz G5 with it’s AGP slot. Any GPU in the slot would prevent it from getting through it’s POST. Unfortunately the damage on this logic board was not repairable (by me) due to an arc burning out the inside of the slot.