Mobo broke while upgrading- help diagnose?

[mjb86]

Hi,
Kinda desperate for some help as my only computer access is now my phone.

I installed a new video card two days ago and cleaned out some built up dust and after plugging everything back in it wouldn't turn on. No response to power button.

I've tried ruling out causes and here's where I'm at: the power cord works on another device. The Mobo has a blue light that is always on when the PC is plugged in- it says C_COMS on the rear of the desktop where the light is. That light IS flicking on when I plug in the power cord and turn on the PSU switch. But it only flicks for a second, suggesting to me a power issue or a mobo issue. I used an extra very new PSU to test the one that was in the desktop and I got the same light flicker which says Mobo issue to me? Were it working properly, the light would be constantly on regardless of whether the PC is on.

Apologies for trouble formatting- struggling mightily as I write this on my phone. Thanks for any advice on diagnosing or solving this!

I have no idea how I could have booked the Mobo just by taking out a video card and putting in a new one unless I damaged it somehow, probably when cleaning out the dust with compressed air and paper towel- never directly on the board, which was still hasty of me.

I'm fine replacing the Mobo, but it's a time-consuming and expensive exercise so I'm hoping there's some fix short of that? Some reason to think I've overlooked something simple?

 

[st6sniper1]

This is a fairly difficult issue to troubleshoot without getting hands on, but I will try to help based on my past experiences.

I have had issues where when I was putting in a second GPU I managed to move a wire connected to the case which caused the PC to not turn on, so is there any lights or any sign of the case itself having power?

It is possible while you were putting in the card you hit a part on the motherboard shorting it or just damaging it completely.


If the board is generally new, there is most likely a warranty where the company will diagnose and fix the part for you, and it is a lot cheaper compared to getting a new mobo.

 

[Kevern_11]

Check in your motherboard manual and find the CMOS jumper. Jump the 2 pins or completely unplug it for 15 seconds. I had the exact same problem not long ago with the lights staying on.