Question Computer Endlessly Power Cycles After Waking From Sleep; Normal Boot After 3 Days

Sep 2, 2020
I have had a power cycle problem for about a week now on a computer I have owned and used with no issue for 4 months (custom built). I thought it was a PSU issue at first when the power cycle problem started so I ordered one from eBay (arriving soon). After three days, though, I decided to boot up the computer to show a friend what was going on (I had just let it be since then - no point letting it power cycle endlessly). To my surprise, it booted up normally right into windows OS. After using the PC for a few hours (which involved stress tests, etc. to make sure the build was stable; it was) I left my room and it went to sleep. After waking it from sleep it booted normally into windows, I was able to enter my password and get to the desktop, but then it shut off after about 20s (strangely the same amount of time it takes to recycle the boot once it's stuck in the power cycle). I booted up the PC again and the boot cycle resumed - it would power on for 20s, get past the bios and some of the windows logo loading then shut off and reboot automatically. I waited 3 days again and same thing - it boots normally into Windows but then shuts off when I wake it from sleep. I have no idea what's happening anymore - I doubt it's a hardware issue since it boots into windows (after 3 days of leaving it be), but maybe there's something wrong in the boot cycle that forces it to shut off?

Any help would be appreciated since this issue is making me lose many hours of work.

The computer has the following specs:
PSU: 4 year-old Corsair AX1500i (has been used in previous builds)
GPU: (used) NVIDIA GTX 1080ti
RAM: GSkill 32gb DDR4 2133mhz
HDD: 1tb Sabrent Rocket m.2 NVME
CPU: Intel i9 9900k
CPU Cooler: Kraken x63


Aug 11, 2020
I'm no expert on these things. If you want to check if there's an error in a windows system file, in an administrator command prompt, type "sfc /scannow" and hit enter. This will run a system scan that lasts a few minutes.