Hello,
I have this out-of-warranty HP EliteDesk 800 G1 SFF (E3S81UT#ABA) that started exhibiting this strange behavior a few weeks ago.
During normal operations the PC is pretty quiet and works normally. Restart works normally too.
But when you shut down the PC, after Windows completing its shutdown process, the screen going in sleep mode, and the external power button led turning off, the power supply (p.n. 702307-001) fan starts spinning at maximum speed and continues this way indefinitely. I noticed that the internal motherboard led remains on. The only way to make it stop it’s to remove the power cord as the power supply doesn’t have any power switch. Pressing the front power button (even for 30 secs) doesn't make it stop.
I updated BIOS and drivers to latest versions. I also tried to issue the shutdown command from a Linux OS, with the same result, just to be sure it was not driver related.
Do you have any suggestions? BIOS settings or such (IME, AMT, ecc.?)
Should I replace the power supply or do you think it’s a motherboard issue?
Thank you.