Hi fellow vintage enthusiasts, I am troubleshooting a peculiar issue with an old socket 7 motherboard and a PCI based S3 Trio64V2. PC posts fine without issue and displays the GPU bios info fine (without lines/artifacting), but as soon as it begins to display the POST information it ranges from white blocks/lines and sometimes partial text followed by white lines as seen attached.
Due to the issue being intermittent I can't determine if it's the motherboard/CPU or GPU, I've swapped the GPU into one of my other machines and it will work fine. If I then swap it back into the original machine it will continue to work fine. The only thing I can say for sure is that when the machine is powered off for a couple of hours the issue will re-appear again. Leads me to believe temperature has an impact on whatever the issue is (dry joints perhaps?).
I've tried the following:
1. Swapped power supply from AT to a newer known working ATX (motherboard supports both)
2. Reseated & cleaned both PCI slot & card
3. Swapped GPU to another machine and then back again
4. Swapped from SIMM memory to SDRAM (motherboard also supports both)
I unfortunately do not have another PCI GPU to test with so unable to rule the GPU out as the culprit.
Does anyone have any other ideas or insight of what I can try next? or alternatively, have a PCI GPU of similar spec that they'd be willing to part ways with (don't expect this for free)? Thanks
TLDR; GPU appears to be flaky but unsure if mobo/cpu, tried troubleshooting and now looking for additional steps to try and or purchase another PCI based GPU.