T30 power/reboot issue

T30 has this issue for months. At the beginning, I have to press the power button several times to show the BIOS reboot on screen. But now it is very weird. It only reboots rarely and most of time I press the power button. The cpu fan is on, but with nothing. The BIOS is not running. Nothing on screen. Just hung there.

Any clue?

I tried the DRAC initialization and others. Nothing helps.