System does not Power on sometimes

[Rocky]

My system does not powers on sometimes when pressing the power button. Then
after some time (maybe some hours) I can hear that it starts to power on (can
hear fan running) and then shuts off again. If I then press the power
button....it mostly starts. (I also noticed that when the system does not
power on ... there is no light on where I connect the ethernet cable
connection).

HELP !!!

 

[Unknown]

You need to try a different power supply.