My computer goes black

Please help!
my computer goes black after a few minutes. the monitor doesn’t show anything just pitch black, but i can still hear a cooling fan inside the cpu working. i press reset button but no respond, i have to pull out the power cable. but it still pitch black if i turn it on. i already change the vga with the new one. but the same problem still occures.

[QUOTE=Bloodlush;2219071]Please help!
my computer goes black after a few minutes. the monitor doesn’t show anything just pitch black, but i can still hear a cooling fan inside the cpu working. i press reset button but no respond, i have to pull out the power cable. but it still pitch black if i turn it on. i already change the vga with the new one. but the same problem still occures.[/QUOTE]

It would good be to first tell us the specs of the computer and monitor? That would be a first start.

first test is to plug in the monitor and turn it on without plugging it in to the computer, you should get some writing come up or also some color bars for a bit, if not…the monitor is probably bad. But if you mean that if you lett the computer sit for a while, then it will work for a few minutes and then go black, disregard this test.

If the monitor shows that is is still good after the first test, and you changed the video card, it could be either the power supply, the motherboard or the CPU. I would start with the power supply.

the spec:
pentium 4 1600MHz
memory DDR 256
MB asrock 775i65PE
VGA NVidia Geforce 4 MX 440
HDD Maxtor 80GB
OS windows XP
Monitor GTC flat 17"

oh i forgot at sometime after the pitch black, when the monitor turn on there is this message “The BIOS have failed to start” something like that. i forgot the real message. is it mean anything.

Sounds like your Video card might be going bad. Just from the specs its a very old card. Here a test take video and monitor and hook each separately to another computer that works. This way you can tell which one is bad and which one is working. Then from that you can deduce whether the card or the monitor is bad. If changing the video cable and power cable doesn’t do that then you have to individually test each components.

[QUOTE=Bloodlush;2219088]oh i forgot at sometime after the pitch black, when the monitor turn on there is this message “The BIOS have failed to start” something like that. i forgot the real message. is it mean anything.[/QUOTE]
Well, maybe just before it goes black the system is suffering a serious fault, then it cannot reboot. Starting to sound like the motherboard to me or a bad power supply. You could try to reset the BIOS on the motherboard if you know the jumpers or you can pull the CMOS battery and wait for a minute, then put it back in. If you are lucky, it might help.