my old PC shuts off after 2-10 seconds

eversysx

Prominent
Sep 29, 2017
2
0
510
I got this old PC with a AsRock P4VM-900 with a AMIBIOS VB53 1999, 512 mb ram, 40gb hdd, dvd rom, fdd etc.
And I recently wanted to see what happens if I boot it up after about 1/2 years. It starts up and runs normaly , even if the fans are loud, but after over 8 seconds it just shuts off without anything saying that on the screen since as I said it starts up normally.
Additional info : Intel P4 2.40GHZ
Powerlink 350W PSU
I hope I can get help with it. I cant upload a pic sadly.