Computer fails to start after being idle for more than two hours.
Computer fails to start after being idle for more than two hours.
Leaving my PC idle beyond two hours causes it to remain off until it automatically restarts. Occasionally it works: turning it off and testing the power button every half hour. Replacing the CMOS usually helps—most of the time it activates without it, then I need to reset it afterward. I removed the motherboard and tried it in another room for a short time, resetting components and moving RAM around. I’m uncertain if the board is vibrating; summer heat and constant AC (around 21°C vs ~32°C outside) are involved. There seems to be a possible short circuit. I double-checked all connections and screws are tight, and no obvious damage was visible on the motherboard. Specs: CPU Ryzen 7 5700X, GPU RTX 3060, Power supply DeepCool 550W, RAM 32GB, Corsair Vengeance, BIOS latest, drivers updated.
First of, what do you mean by it won't power off? Are there any error code/beeps, is it just black screen. Do the motherboard light up? Being an MSI board, that should have the led easy debug(cpu,ram,gpu,boot), is it stuck on one of them? Is there any sounds? But just going by what you said, if this is my pc, the first I would be testing is really to check if there's any short. Then probably the psu or gpu. So when you say "taking out the motherboard and test-benching it in another room for a bit(Reseating things and moving around RAM)" What do you exactly do? Does it turn on everything you do this? What I mean is, when you remove everything from the case, and put everything together on top of the motherboard box(for example). Removing everything and just install, the basics, cpu, motherboard, one stick of ram, psu and just one storage(the one with the OS), making sure that every usb are disconnected(including the one that connected to the front panel of the case) and even fans. When you turn it on, it should still turn on, but will have an error like "no gpu detected". If you encounter the same issue already, that means, at the very least, there's an issue in one of those parts. So you test another ram stick, or PSU or CPU(if you have extra parts. If it turns on and you get the no gpu error, then the next step is to add the gpu in. If it still turns on, then add another part, like two sticks of ram. Until you connect every parts, while examining every cable for cuts, flatten, bent pins, etc(including hdmi/DP).
During testing, I usually remove everything and reinstall, aiming for POST with just RAM, CPU, GPU, and OS storage. It usually works, then I put it back in and it functions properly. However, after leaving it off overnight, it stops responding completely—no lights, no fans spinning, and the next morning it fails entirely. When I disassemble and reassemble, sometimes it works again; other times, changing the CMOS battery or re-seating the CPU helps. It’s confusing to determine exactly what’s causing the issue. Rebuilding the whole system every day is frustrating. I’m trying to figure out what’s preventing POST, especially if leaving it plugged in and powered on overnight drains the CMOS battery. I’ve tried different CPUs and RAM sticks when it doesn’t work, so it seems the problem might be with the PSU or GPU/MBOB. What part of the rebuild actually resolves the issue? Please let me know if you have more questions and thank you for your help.
Have you considered leaving everything on the test bench overnight to check if it functions the next day? Regarding the PSU, if it operates correctly, it shouldn't be an issue. Please confirm if my understanding is right—my only thought is that a PSU might fail intermittently due to a broken fan causing overheating. This could be a short-circuit, possibly from sagging cables. If so, the next step would be to stop using your current case.
Thanks for waiting. I believe I located the issue. The GPU and CMOS were removed last night, and the PC managed to POST and boot again in the morning. I’ll check again tomorrow morning to confirm.