My computer always ask to set CMOS set up during boot up. i think my CMOS has problem and i tried to clear the CMOS by using the jumper for clear CMOS. i did not unplug the PSU when i did this and after i return back the jumper and start the PC i don't get and response. i can't even enter the CMOS set up. what could be the problem? is my motherboard breaks down?
You sure that you've entered the jumper to his correct pins?
Anyway, as you described it (that you have to setup the CMOS every time you start up your PC) it sounds like the CMOS battery is probably dead. If you setup the CMOS every time, and it still asking you to do a setup - I'm almost sure that the battery is the culprit.
The possible solution for your problem is really cheap - replace the CMOS battery. I will guide you how to do this:
That's it. Just plug in the battery, and see if it solved your problem. If the problem stay unsolved, note that the PSU / MB can be also the culprits.