Computer problems, screen keeps going on and off every 3sec.

I have rebooted the computer and same thing; I cheek all the plug-ins and still the same. In fact, I'm having to turn the screen on and off to write this.

Could anyone help me out?

Swap CPU monitors and see if the problem persists.

Could be any number of things.

1. When's the last time you ran a virus check, a spyware check, adware check. Run all those first to see if you've gotten a virus or something. I say do this first because it doesn't require much effort.

2. Have you tried doing a system restore? Try that next.

3. Do you have another monitor you could hook it up to? Try that next. If it's doing the same, move onto #4.

4. Possible bad video card or a corrupted driver. Make sure you have the latest driver for it or at least have the disk for the video card/motherboard before uninstalling video card. Reinstall the video card and reload the driver.

It's always a good idea to post what your computer's specs are. Processor, onboard video, amount of RAM, Operating System (OS), etc.

Swap CPU monitors and see if the problem persists.

I hook every thing up to my laptop, and it's working fine!

what do you mean by going off? full shut down? is it locking up? are we talking lap top or desk top? does the tower seem to still be working?

If you are experiencing full shut down, then the computer might be overheating.  I had a fan go out in my old computer that caused this problem.

It could be the back light on the monitor. Do you have a flat screen or a CRT?  I just replaced mine after 3 years and that is exactly what happened before it died.