Computer won't boot

[petehern]

Symptoms:
When I turn on my computer, the fans kick in and the drives spin up, but the screen is blank. The hard drive and dvd activity light stays solidly on for about 10 seconds after I turn it on, then turns off, but power remains on.

System:
Shuttle XPC SG31G2S (not overclocked; onboard video)

Things I've tried:
I've tried plugging in a different monitor; still nothing.
Clearing the CMOS

How this all started:
I took my computer to a LAN party (it had worked fine for months). Someone tripped over the power cord. When I plugged it back in; it wouldn't boot. My friend fiddled with the cords (he *did not* open the case) and eventually got it to boot. (He said he pressed the power button in and held it). Computer ran smoothly for several hours, shutdown normally and I took it home, where it once again would not boot.

 

[jackschmittusa]

Pulling the plug while it is running can cause an arc which can cause a number of things to happen like a huge voltage spike or excessive heat. Any one of your components could have blown caps, diodes, and resisters.

Time to pull the mb and try with the bare minimum, and if it works, add a part at a time.

 

[petehern]

Thanks, Jack, I'll try this.

If this fails, what's my next best thing to try? Replace motherboard and power supply?

 

[petehern]

Running the motherboard with the bare minimum, still doesn't work (though no hard drive lights this time).

What's next?

 

[jackschmittusa]

I would test the psu with a multimeter next. Plenty of instructions online. If you don't already own one, borrow one or buy an inexpensive one. Good thing to have around the house anyway.

It may well be the mb, or possibly (but less likely) the ram.

 

[Laputa]

You can try to hard jumper the power on switch to see if you have a bad power on/off switch, but sounds like you may have a bad power supply.