hp 500b mt start then goes off

[mjaka]

when i start my computer it start then goes off for about 30 minutes. when i tried to boot the screen goes black and led power blinks randomly without define pattern. if i left for some hour it start up for 30 min again. RAM test i perfomed it seems is ok. i real need an help friends any body may answer this

 

[Phillip Corcoran]

Try a new PSU.