Question New mini PC build kept randomly going into sleep, now it won't load Windows ?


Jan 21, 2022
First off, I've built dozens of PCs and never have never seen anything like this. However, this is my first mini build. Here's the parts rundown:

ASRock Mini-ITX Motherboard (B450 Gaming-ITX/AC)
AMD Ryzen 5 5600G
Corsair Vengeance LPX 16GB (2 X 8GB) DDR4 3200 (PC4-25600) C16 1.35V
DC 12V Pico PSU ATX Switch
AC 100-240V to DC 12V 10A PS (120W)
Goodisory 0.6mm SECC Mini ITX case
Windows 10 home

I built this for my daughter to play Genshin Impact. It ran perfectly for about 3 weeks then it would randomly go into sleep mode (blinking power light) after playing for a few hours. It wouldn't wake using the keyboard or power switch. Unplugging it and plugging it back in worked the first few times.

Then it started happening more frequently. At first I suspected overheating, but things seemed to be running fairly cool. Also, I couldn't get it to work with a simple unplug/plug-in anymore. It would keep booting into sleep mode unless I left it unplugged for an hour or so.

Then it started happening outside of playing games. It would go into sleep mode just by opening chrome. I updated to the most recent display driver to no avail.

I tried a Windows restore point from a week before this started happening - no difference.

Finally, I made the desperate move to wipe the SSD and do a fresh installation of Windows 10 from a USB drive. Now I can't even get it to boot into windows. The system posts just fine and I can get into the system bios with no issue. But once I exit the bios menu and try to load Windows, it goes right back into sleep mode with the blinking power light. I even tried a second reinstallation of Windows with the same result.

At this point I suspect faulty hardware but am not sure where to start. Part of me thinks it could be a bad PS or Pico PSU, but I would expect this to prevent the system from POSTing.

Maybe it's an SSD issue?

Does anyone have any suggestions on where to start troubleshooting?