Built computer doesn't work :-(

[Dina Lerret]

The computer I was building doesn't work.  Almost same problem as this person:
http://answers.google.com/answers/threadview?id=436180

I have an Intel motherboard and Pentium processor, but mine never
powered up at all.  Man, I have to troubleshoot this puppy.

The LED light next to the motherboard power supply and RAM lights up,
even when the computer isn't turned on--as long as the backswitch is
on.  I turn on the computer and the front power light comes on but
none of the fans turn on (e.g. CPU, power supply, and case fans, which
aren't hooked up to the motherboard--they're hooked up to a 'hardcano'
on the Thermaltake case, which even that display doesn turn on and I
know all plugs are hooked up to the power plugs.

I've already ripped out the floppy from my 1995 computer and the PSU
on that puppy is like 100-150... Hm, maybe I'll try ripping that out
and see what happens.  Gah, I hope it isn't too old.  Though, I was
thinking about upgrading the included 420 PSU that came with the
Thermaltake case with an Antec 550 PSU.  Err, bought the case off eBay
too.  Motherboard is new, unless I fried it by accident.

Good thing my tax refund is $1200+.  {sigh} Learning experience, I
just keep telling myself.  Sadly, I'd rather piss away my refund on
this frustrating project than go on vacation... That's really pathetic
in a 'I have no life' scenario. {chuckle}

Dina