PC won't turn on

I would check the power supply. If you do not know how to properly test it then I would replace it. If that does not solve the problem the MB may have failed. But it really sounds like a PS problem.

You did not mention if there are any beep codes during the boot process.

When booting try entering the CMOS setup by pressing designated key to check the BIOS configuration.

Has the board been overclocked or have you expierenced any overheating lately,sounds like a overheated cpu or motherboard gone bad.

Use a startup disk and remove all hardware except video card and memory,try booting.

Check cables to insure they are plugged in correctly,if you recetly worked inside the case

Before you search further, please consider the following: you HAVE power because the red light turns on... the fan won't run, so the most simple answer is: the damned thing is dirty... The fan attracks lots of dust, and hair... I think that's why it blocks. Beware, if the cooling doesn't work properly, you might get some bad sectors on your hard disk. So open your pc and clean up the dust..

I've had experience with some machines that put the power supply into some kind of comatose state, even after unplugging and re-plugging the power cord. The cure is to press and hold the power button for approximately 15 seconds, then try to power up.

Worth a shot, and if it works, a cheap fix! (though I'd still check/replace the CPU fan)

I had exactly the same problem. I tried my power supply on a different PC and it worked fine. I eventually bought a power tester screwdriver (about ?4.99) and tested all the diodes etc on motherboard, and found several loose connections. Pushing them around sort of solved the problem, but very tempremental. If you have chcked that the on/off switches are not loose etc, it would probably be better to get a replacement motherboard

You didn't say if you had done anything to your pc before the trouble happened. If by chance you played with the drive cables in any way, try unplugging the cables and see if it starts again. A cable on wrong way WILL stop the MB and all it's parts from running

ok My two cents worth
rick

Well, It sounds to me like you have the BIOS reset Jumper on.. Some Taiwan boards come with the Bios Reset Jumper in the Active position (dont ask me why), which you will need to remove (or move) to a different setting. Whats happening is every time you power up it resets the Bios.. clever hey!..
best thing is to check the Jumper setting in the manual or the web site.

Hope that helps!

You may also want to check the back of the power supply and make sure it is set to the right input voltage. They usually have an option for 115v and 230v. Try switching and see if it works. The switch is usually a small red sliding switch near the power supply's main switch.