I have an IBM Aptiva Pentium 120Mhz with a S3 Trio card for graphics (the on-board chip is rather slow). It worked fine for ages but last week I booted the PC back up to connect a RetroTink 4K between the PC and monitor and after about an hour playing suddenly the image cut out. I could hear the game continuing and initially thought it was the video cable so I went to press the power button to turn off the PC and ... the image came back on! Not only did the image come back on, the PC did NOT shut down as usual?

If I were to take a guess it would be something connected to some power saving feature which these IBM PCs had (Rapid Resume it was called) but it's all turned off in the BIOS and of course, I'm actively using the PC so it has no reason to go into sleep mode.

Does anyone have any idea what it could be ? Could the Retrotink somehow cause this issue? It seems unlikely.