Question Troubleshooting issues when it won't send anything to the monitor

Jan 12, 2023
I'm currently working on my son's computer, which I built 3 years ago for Christmas. It started with the fan dying on their video card around New Years, so I ordered a replacement and swapped it out. When plugged everything back in I got no display, and the beep code of long-short-short-short. This was on a Gigabyte 450M motherboard. The internet suggested this to be a memory issue so... here's what I've done so far:
  • replaced the RAM (ordered new Corsair) - no fix, same beeps
  • removed their video card - no fix, same beeps
  • disconnected SSD - no fix, same beeps
  • replaced the MoBo (ordered an MSI 550) - no display... no beeps (see below)
Ran into a neat new problem here, which had me tearing things down and rebuilding. At first it wouldn't even power on with the new MoBo... got that fixed. In the process, I ended up breaking the onboard/plugged in speaker, so now can't hear the post beeps.
  • tried the video card from MY computer in theirs - no display, waiting for replacement speaker to arrive
  • Additional tests:
    • tried their RAM in my computer. works fine
    • tried their video card in my computer. works fine
    • pulled the battery to reset their CMOS
What I haven't tried yet:
  • replace their CPU with MY CPU (not that eager to do so)
  • throw it out the window
Parts list in their computer (to start):
  • Gigabyte B450M DS3H (installed Dec 2019, no problems)
  • AMD Ryzen 5 2600 (installed Dec 2019, no problems)
  • OLOy 16 GB RAM (installed Dec 2019, no problems)
  • Samsung 860 Evo 500GB (installed Dec 2019, no problems)
  • XFX Radeon RX570 8GB (installed Dec 2019, no problems)
New parts I've tried:
  • Corsair Vengeance LPC 16GB (didn't fix anything on the old MoBo)
  • PowerColor Fighter Radeon RX 6500 XT (from MY PC, built Aug 2022)
I'm at wits end trying to figure out what I can try, not being able to mess around in the BIOS doesn't help. If I need to flash/update the BIOS in the new MoBo... I'm not sure how without a display.
I'm hoping someone that has encountered this, or who builds "modern" PCs more regularly can offer some input.



PSU: make, model, wattage, age (3 years?) , condition (original to build, new, refurbished, used)?

How full are the disk drives?

History of heavy gaming use?

Try a new CMOS battery as a matter of elimination. (Refer to the motherboard's User Guide/Manual regarding how to reset CMOS.)
Jan 12, 2023
As is so often the case, it worked itself out. I tore down again, had parts all out just on the bench and started testing. (the speaker arrived so i hooked it up to hear errors)

When I re-assembled on the "old" motherboard, I went ahead and applied thermal compound for the CPU heatsink. I plugged everything in naked, but just one stick of RAM and I got a display and everything going fine. I adding the second stick, still good, so I rebuilt the computer with all of the original pieces and it booted fine. I unplugged/replugged everything multiple times in the past week so not sure how anything was not seated properly. Is it possible the lack of fresh thermal compound caused problems?

So... "solved" but I don't completely know what the fix was.