All computer experts, some help?

[NJNETSFAN15]

I don't know the exact error, but this compaq I recently rebuilt, won't work. all cables are functional, but it doesn't leave the "compaq" screen.

I've narrowed it down to a couple possible problems.

CD drive is broken,  I KNOW this much.
Possible Hard Driver failure ( No idea, but it is a very old hardrive)
Video card ( some cables were missing. Now, I don't think it's nessecary, as the display is fine, but this is a possible problem)
Processor Heatsync I didn't add it, simply XP This is my first full blown computer built from scratch, and I don't know how important it is to the actual running of the computer. I figure this would cause overheating, instead of the computer not starting up...

Which of these do you think is most likley, and should be fixed first?

[NDS]

When my CD drive was jammed, yb computer wouldn't go past the "HP" screen, so I'm assuming that is the problem. Good luck.

[Judas]

Um, yeah, it's the heatsink. You need it. The computer won't even stay on for more than like 3 seconds (or shouldn't, at least) without it.

[NJNETSFAN15]

Hmm, I can borrow some heatsync from my teacher for like, 30 cents, so I'll try that. I'll also swap CD drives with my older computer. I'm hoping it's compatible.

[Mystic]

Compaq is your problem >_>

[Drybones5]

Compaq is your problem >_>

QFT

[えっちーせんぱい]

Hmm, I can borrow some heatsync from my teacher for like, 30 cents, so I'll try that. I'll also swap CD drives with my older computer. I'm hoping it's compatible.

You can't BUY heatsink, you ca BUY a heatsink, but yeah xD

[Hiei]

Hmm, I can borrow some heatsync from my teacher for like, 30 cents, so I'll try that. I'll also swap CD drives with my older computer. I'm hoping it's compatible.

You can't BUY heatsink, you ca BUY a heatsink, but yeah xD

They probably mean thermal paste

[えっちーせんぱい]

Hmm, I can borrow some heatsync from my teacher for like, 30 cents, so I'll try that. I'll also swap CD drives with my older computer. I'm hoping it's compatible.

You can't BUY heatsink, you ca BUY a heatsink, but yeah xD

They probably mean thermal paste

Reminds me...

Do you happen to know the normal operating temprature of a P4 2.4Ghz prescott? I get about 122 idle, and 144 after 30 minues of web browsing.