PC wont post with gpu in, no USB power, no power light, no beeps. Broken motherboard?

Jul 8, 2018
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Hi everyone

A few days ago I found my PC wouldn't turn on, not even reaching the bios or anything. As well as this some of the system lights and none of the USB ports were powering on. The CPU fan was working though.

I thought it could have been due to a power surge, since my house had had some kind of power surge or cut earlier that day, although the PC was off at the time.

After some fiddling I found that unplugging my GTX960 from its 6 pin PSU plug, but leaving it in the motherboard socket would allows the PC to power on, but only via the motherboards display adaptor.

At first I thought the issue might be the GPU, but I tried a brand new GTX1050 TI and had the same issue. (This card only plugs into the motherboard, there's no PSU connection needed) The PC wouldnt post when it was in the motherboard. The cards fan did spin though, which the 960s didn't but I'm pretty sure the 960 is fine.

When there's no GPU the system seems to work normally, the HDD is fine and all the other hardware is recognised and seems to be functioning normally, making me thing the PSU may be fine.

I've tried resetting CMOS, ensuring the PCI was enabled and set to the default in the BIOS, and ensuring the cards were properly plugged in, but dont seem to be having any luck.

I'm suspicious of the motherboard (ASUS m5a78l-m/usb3) since its a 4+ years old and has been slightly faulty at times in the past, though only in minor ways (unpowered USBs ect)

Does anyone think this could be an issue with the motherboard or its pci slot? Or an issue with the PSU? Thanks
 
Jul 8, 2018
2
0
10

Unfortunately I don't have a spare PSU, so im not able to test that. Everything else seems to be functioning as expected though, and the GPU fan starts up when its plugged in even if the PC doesnt post. I might have to pick up a new motherboard anyway, since the current ones getting old and if it still doesn't work I could always get a new PSU.