Hello,
The motherboard and power supply can contain a charge for a considerable amount of time to the point it can act like a battery too so you might need to discharge those if you didn't wait long enough.
Turn the power supply switch off / mains plug.
Remove the battery or use the clear CMOS jumper.
Like this press the computer case power button and hold it down, 2 seconds, you might see the board attempt to power up for a millisecond. Do that again and it should now be completely discharged.
Wait around 2 minutes.
Then put the battery back
Turn the mains switch back on and see what happens.
Also remove the nvme if you have not done so already
Hopefully this helps?
