Computer won't POST

[tikal]

For some reason my friend's computer won't POST anymore. He has a mini-ATX mobo with a celeron 600 cpu, video and sound is integrated. It seems like there is no video for some reason.

This is what happens:

Power on, cpu fan spins, hd spins up, for some reason the loading light is a solid green. No video. I can't reset the system either. Then after a few minutes the cd-rom tray pops out. Still no video.

I've done/checked:

Tried a different monitor.
Tried a pci video card.
Took out the RAM, I believe I should hear some beeps, none.
Checked the motherboard, cpu, and ram and nothing is burnt.
Changed the powersupply

I can't really think of anything else to do...

My friend told me that his younger brother has been turning it on/off many times, could that have an effect?

Any help would be appreciated...

[tazdevl]

If you aren't getting any beeps on the RAM, chances are the mobo is dead. Try pulling the graphics card as well, should get a couple beeps on that.

Turning on and off the computer wouldn't do it. He could have been using a substandard power supply which can kill components quite easily.

If this was a new installation, I'd think the motherboard could be shorting itself out somewhere, but this isn't the case.

[tazdevl]

Or the processor is dead. Was it overclocked?

[tikal]

Nah, the cpu wasn't o/c'd.

What I don't understand is if the motherboard is dead then why does it still turn on? I mean if the motherboard is dead it shouldn't even turn on from what I've experienced.

Thanks.

[TheWizard]

What are your indications that the motherboard "turns on"? Or are you mistaking the "turning on" to be the power supply? It is true that if a motherboard is toast, it usually will not even power up. However, to clarify, I'm wondering what exactly "turns on".

In order to find out for sure, mount another compatible and known to be working CPU on the motherboard. If it still doesn't POST then it's most likely the motherboard. If it does POST then you know the processor on the motherboard now is bad. Of course, there are always other possibilities, such as a bad power supply.

[blakerwry]

you dont have to OC a CPU to kill it... 1) heatinsk needs to be on correctly.. there are 2 ways and only 1 of them is right. also there needs to be thermal compound...

If you're not getting beeps and "it was just working yesterday" then my guess is the CPU.

[CDRecorder]

Try booting up with the board out of the case (set it on some cardboard or something). If it works that way, it's shorting out inside the case.