In order to start my computer I have to unplug it, wait for 15 minutes and then:confused: plug it in, press the power button and hope it starts. It may take several tries before it catches and stays on. Please help.
Thanks, bob

What exactly do you mean "before it catches"? What exactly happens when it don't work? Does it not do anything, or turn on for a minute, then turn off?

The computer turns on for about 3 seconds then turns off. I have to go through the unplug, plug routine a few times for the computer to stay on.

Sounds like a power supply problem, maybe a short-circuit or overload somewhere, and the built-in power supply protection is shutting it down.

Did this happen recently?

Open the PC and check that all cables are in good condition (i.e. no bare leads, no frayed insulation, etc.).

Remove the power plug for all components, except the CPU fan, and the video card if it uses an aux. power connector.

You will only be able to get into bios, but this check is to see if it starts up right away, instead of getting lucky...

If it does work on the first restart, try a few times to make sure its starting reliably, we can now narrow it down to a component problem.

Plug the power into one component at a time (i.e. hard drive), and restart. Repeat the above.

Plug the power in for the next component (i.e. cdrom) and restart. And so on.

This can help determine if a component is at fault.

In order to start my computer I have to unplug it, wait for 15 minutes and then:confused: plug it in, press the power button and hope it starts. It may take several tries before it catches and stays on. please help.
thanks, bob
Sounds like it gets hot have you ever took cover off and cleaned it carefully are your fans working are the clean also sounds like bad connection.. power cable or could be groundening out check all cables and connections

Another thing to try is to unplug any USB devices, that may sound weird, but I've actually had a USB mouse make my computer do the same thing. The minute I unplugged it, it worked fine. If you've added any extra hardware, you may want to try to remove that as well (sound card, video card etc.)