I recently switched my system to a full Linux Mint install after dual booting for a couple of months. Everything went smoothly during the installation, but now my PC goes to sleep after about 15 minutes of inactivity. When I try to wake it up, nothing happens. The power button is unresponsive, and the CMOS reset button does nothing either. My USB mouse lights up, but that's about it. When I drain the power and plug the PSU back in, there's a brief flash from the PCIe network card, but it goes away quickly. I've already checked the PSU and done the jumper pin test, but nothing seems to help. Has anyone experienced this? Any ideas on what could be wrong?
2 Answers
This sounds like it might be a hardware issue. Generally, the operating system doesn't affect the behavior of the hardware before it loads. If it was working fine before the install, I’d check all connections and maybe try reseating the RAM or GPU. Sometimes just pulling everything out and putting it back in can do the trick!
Have you tried resetting the CMOS? Removing the battery for a few minutes can sometimes clear up strange power issues. It might resolve the waking problem if it’s related to the motherboard settings.

Yeah, I had a similar issue once where I just needed to reseat my GPU. It can be frustrating, but it's worth a shot!