pc shuts off.. but all is running? no screen.. then

[jackthedude]

i seem to have a prob.. my pc booted up and then after a few min.. screen shuts ?? i hear pc runnin but as if it is shut off..?? but i hear system runnin.

i had this problem happen last week.. my pc was runnin.. then it started shuttin off and restarting.. now.. it has shut down in a way.. i hear like fans still running and so on runniong but no screen.. really weird.. ithappened tonite again.. and so i shut off pc.. opened box.. and tried to take out all and replace.. make sure all is clean and intact.. so i then afte putting all back.. started pc.. and it started.. and then liek 10 -15 min later it shut off again.. as if pc was in sleep mode.. no screen but i hear system workin.. wut could this be?? i am on win xp//./ p3 it is usually a great pc.. LOL

also now.. it will start up - no screen and pc runs for a min or 2 and shuts ? what do di do do i need new motherboard?? do i need new cpu? do i need both????? somebody help me pleaseeeee

[VERCETTI]

How long you been using this pc before this started? Years, months? Sounds like a mobo problem if your PSU is good.

[Cricket]

Cross post.

Cricket

[jackthedude]

been at least a year on this mother board
... its odd.. so can i chaneg my mother board without changing cpu?? how would one know if cpu no good anymore??? i dont think its my hard drive.. i dunno if it could be mobo or cpu or vid card.. ???? could it be i need thermal grease???

[glc]

I closed your crosspost. Please answer Cricket's questions from your other post here.