Jan 5, 2022

I've been using and building computers for almost 20 years as a hobby and this is the first time I've run into a problem that I don't know how to fix.

Here's my issue:

First off, my computer worked fine for about to months without any issues. Then, after a reboot, it stopped feeding a video signal to my moniton. So, in true old troubleshooting fashion, I started with step 1: rebooting mutliple times as well as disconnecting and reconnecting all the components.

When this didn't work I resorted to step 2: trying different components.

I tried three different GPUs, four different RAM sticks, two different CPUs, two different power supplies, two different monitors, two motherboards (just to make sure it wasn't an issue with the motherboard itself), and even a different case and
a professional test rig setup in the form of a cardboard box, just so I could rule out a potential short. All of these components are confirmed to be functional. I also reset BIOS by removing the battery, using a jumper, and waiting for about 15 minutes.

As is standard practice, I double, triple, and quadruple-checked everything, but still no VGA signal. This made me very frustrated, so I had to bust out plan C: sending my motherboard and CPU off to the retailers for some professional troubleshooting.

After about a week I got a phone call from the retailer where I purchased the motherboard. He told me they were able to boot the motherboard just fine and they couldn't find anything wrong with it. The same thing happened with the second retailer
where I had purchased my CPU. The first retailer technician was also kind enough to update BIOS to the latest version.

Here's what I actually do know:

  • The "VGA" debug LED on the motherboard lights up and doesn't turn off.
  • At startup, the monitor power LED turns green for a few seconds. The LED then turns orange and I get the standard "no signal detected" prompt. It clearly detects something. However, the most likely explanation for this is that it's just the monitor detecting that there's a cable connected.

I'm completely stumped and I have absolutely no idea what the issue is. Can someome potentially help?

My specs:

Motherboard: MSI A520M-A PRO.
CPU: AMD Ryzen 9 3900XT.
GPU: ASUS GeForce GTX 1660Ti, 6GB.
RAM: 2x Corsair Vengeance LPX, DDR4 16GB.
Power Supply: XFX PRO 650W.

Thank you!


Welcome to the forums, newcomer!

Thank you for including as much information as you did since troubleshooting is not for the faint of heart and does tend to reduce brains into spaghetti. Though if I may be candid, you forgot a couple of key mentions in your steps. You forgot to mention all the spare hardware that you'd used to troubleshoot the system, generically mentioning parts/devices often does leave some things to the side.

In fact, here I was thinking that the board croaked, but after reading that the store you purchased the board from got it working, then made me think you might be having a grounding issue(since system's working in place but not the other is often a sign of a grounding problem, considering how everything was constant aside from the wall outlet, until I read you sent out only the board and processor). Please mention the parts they'd used as well to come to the conclusion that the board and processor are in working order.

How old is the existing XFX PSU? A side note, that VRM area on that board is a first thing that would put up red flags when working with a flagship processor from AMD's Ryzen portfolio.