HP Z820 Not turning on

[BasFP]

Hey,

I have bought 2 Z820 a couple years ago, but since a couple months if you turn down the computer come back the next day and try to boot the system. The HP just doesn't boot. The power button LED turn on if you press the button but the pc doesn't boot. If I do this for around 10 min. Pressing the power button holding it for 3 sec and releasing it, it will eventually  turn on with this method but it is very annoying and time comsuming.

The Driver/firmware didn't change. I did remove the BIOS battery to see if this works (doesn't).

The only thing that is updating is the Avid version en Windows Version which update automatically.

Hope somebody can help me, for more information please ask.

Kind Regards,

Bas

[BasFP]

I Have replaced the power supply this didn't help so I started using the old one again.