Here are comp specs
Case: Antec Super LANboy
PSU: Antec SmartPower 2.0 500W
Motherboard: Intel DP965LT
CPU: Intel Core 2 Duo E6300
RAM: Patriot DDR2 667 PC5300 2GB model PSD22G667K
Video card: ATI Radeon X1800XT 512MB
Ok so when I try to boot the computer, everything turns on but nothing shows on the screen except for a solid underscore in the top left corner. All the fans are working and there are no beeping sounds. The keyboard lights flash on and off right at startup (like it usually does) then they turn off and the num lock light turns on, but the keyboard then stalls also (pressing num lock won't turn its light off). The CD Drive can open and close also (the CD Drive light is also permanently on).
Also I noticed that whenever I plug it into the power outlet the computer will turn on by itself for a couple seconds then turn off (at least the fans and the blue light in the front of the case turn on)
I double checked to make sure that the LED cords are all plugged in correctly. I have the three hole Power LED plugged into my motherboard's alternate front panel power LED. The Reset SW, HDD LED, and Power SW are also plugged in. I have a LED cord (which is literally just labeled "LED") which has yellow and a white wire that I don't know where it goes to so I left it unplugged (I tried plugging it into the original Power LED slot but it didn't change anything). I might still have these wrong but I don't want to go back through them if it's not the problem.
Make sure the HDD is connected well and that everything is seated correctly. Try booting with the OS disk in the CD drive and see if anything comes up. Before that, reset the CMOS by taking the battery out for a few minutes, making sure the PSU power switch is off if you have one.
is the turning on then off by itself thing normal?
edit: alright so I fixed the automatic turning on thing...
So now, the first time I hit the power button, it will turn on for a second then turn back off. I press the power button again and it goes back to what it was before (with the underscore in the top left corner)
ok so could it really be the hard drive? It's a Samsung 160 GB Serial ATA drive. My dad said it might not work when he gave it to me. I have the red SATA wire connecting the motherboard to the hard drive and the SATA power connection from the power supply to the hard drive.