system is not booting

[sayed]

i have pc.when i power on the cpu,the cpu is starting the fan is running all lights are glowing ,there comes the beep sound and it is not booting (i mean the monitor is not displaying,,)the power supply to the monitor is ok. when i start again after couple of hours it work normally, after an hour or so it abruptly turns off (display turns off,,,cpu is working ).....when i start after several hours from the problem occurs ,,it works normally for several hours..plz help me....

[Whyzman]

I've moved your thread to a more appropriate forum.

[Whyzman]

The single beep tells us that the pc has booted. How old is this computer? Have you looked inside to make sure the motherboard and fans are not full of dust. Your power supply could also be full of dust. Be sure to turn all power off and unplug before servicing.

[FTT]

Yep, clean out the dust bunnies for starters and try another monitor if possible. If that's not possible, next time it goes out, shut just the monitor off for about 15 minutes and then turn it back on. If the display returns, it is most likely your monitor.

Does this PC have built in video or a dedicated video card?

System specs please, model and series etc...