mobo: NF7-S cpu: Athlon XP 2500+ video: Radeon 9600 pro Dear all, I've been experiencing weird things with my PC lately. First, the CPU speed dropped from 1.8ghz to 1.0. Then every time after restarting, it would not boot and show anything on the screen for a while. Now, it totally stopped working. By hitting the power button everything powers up, but there's no beep which indicates that the computer has been turned on. This can't be ram or graphics card or any other such components since it doesn't matter for the screen to display anything. I suspect it is the CPU or the motherboard. I've checked the mobo manual and made sure everything is set correctly on it(jumpers, etc), reset the cmos battery and such, replaced the fan with thermal paste, still no result. No symptoms of fried parts or anything of that kind. Any other ideas would be appreciated! Thanks.

Motherboards and cpus rarely go bad spontaneously, although they can be damaged from external causes, such as power spikes or surges, or a failing power supply or overheating in the case of a cpu. The second part of your symptoms are a lot more likely to be caused by something else. Failing power supplies are common and can cause those symptoms. Check your PS. See response 4 in this: http://www.computing.net/hardware/w...

Thanks for the response! How do I know if it's a PS? It powers up all the other components such as HD or CDRom. All the fans are working and there's no burning smell or anything.

If the posting screen is showing the lower speed, the FSB or multiplier settings may be set wrong in cmos. But that shouldn't cause the additional problems you're having. When you reset the cmos battery the speed should have defaulted to minimal setting. Just because the fans and drives fire up doesn't mean the PSU is good. A motherboard needs additional voltages not required by the drives so a bad PSU may still power them up.

I see, in that case does best buy allow to return PSU if opened? I need to get a power supply I guess to test it out.

I wouldn't want you to think the PSU is definitely bad--just that the fact it power the fans and drives doesn't guarantee it's good. If you're talking about buying a PSU to test and then returning it if there's no change, I guess you'd have to check their return policy. It seems like they'd take it back. You may want to disconnect all the drives and remove all the cards except video and then see if you at least get a posting screen. If so it's likely one of the removed devices is the problem.

To confirm it's the power supply, you could temporarily connect a friends computers power supply - make sure all the wire colors and numbers of wires on the main connector from the PS are the same - or you could take it to a local computer builder or repair place and have them try another power supply but they may charge a small fee. Removing a power supply is a simple matter on most computer cases - 4 screws on the outside of the case where the power supply fan is, unplug the connectors.