solve my prob plz

My computer is having a strange problem

What it seems to be doing, is it turns on, and then resets, and then resets, and then resets, and then sorta maybe gets somewhere (the monitor comes out of sleep) then goes back to sleep.

The power LED seems to be flicking on and off. The discs spin and stop and spin. The DVD rom LED blinks. The MB light is always on. The wireless reciever for the mouse and keyboard turns on.

At one point (the first time) I got the feeling maybe it was trying to boot from a CD, so i clicked it open, and it opened halfway and then turned off completley.

Also of note, I rarely shut this down. It was probably powered on without a shutdown for a good few months. Then I went away for the weekend and shut it down. Got back, went to turn it on and this happened. Nothing has changed, so I have no idea what this could be! I tried the RAM, i tried the CMOS battery. I checked the power cable. I havn't gone in and checked all the little ones, its late and i'm tired.

Any help is greatly appreciated however. So many thanks to those that can offer it.

How old/what quality is your power supply unit?

It might be a problem with that, or possibly if you're running a device that's feeding moe than usual from the PSU.

I've had a similar problem and resolved it by replacing the PSU. You probably wouldn't want to shell out the $50 or so dollars (or $30 on newegg.com) to buy a new one until you know for sure... so I'd recommend borrowing a power supply from another computer and testing it out that way.

my power supply is relatively new. infact all my cpu is abt 9 months old . i'll check my power supply . plz comment more

The sort of breakdown or malfunction has nothing to do with relatively new-ness basically. If CPU is bad, it usually hang up there.

In addition, your PSU. is not completely broken, but is losing its strength. When devices is spinning up, they need max-power to initialize itself. If there occurs shortage of power then, they must reboot. Other causes that is thinkable is that there may be extraordinary power-eater. So much so that, you'd better remove all unnecessary items one by one until it boot up.