So I'm working on an older computer, an HP well past its warranty. It has 512 megs of RAM, a P4, and GeForce Ti4600 or something similar (AGP slot). The computer has been working fine. A while back the DVD drive (IDE connector) had a disc break inside of it, messing up its gears and READER, so I bought a new drive and installed it. I also plugged in a RADEON 9800 and an additional 128 megs of RAM. I tried to turn the computer on, and all everything lights up, fans spin, I can hear hard drive, etc, but I get nothing from the monitor but an amber light. I put back the old video card that worked, removed the new RAM, but kept the new DVD drive in, (because even if something is goofy with that, the computer should at least be able to reach BIOS and begin to boot). I have checked the stupid stuff, i.e., making sure the monitor cable is properly plugged in to the video card, making sure the RAM is seated CORRECTLY, making sure all cables are plugged in, etc.

To summarize, the machine is in exactly the same state in which I started working on it, except it now has a new DVD drive plugged in. But where as it worked fine before, now it won't even start to boot.

Any ideas as to what could be causing this? pop out your CMOS battery (the only battery on the board) and wait 30 seconds, then pop it back in. do this while the computer is off and the power supply is shut down.Well, I tried popping out the battery like you suggested and no luck. I think the mobo may have gone *censored* up. Not sure why it would have, maybe there was a bad soldering job or something and I knocked something loose when I was poking around inside the case, that's really all I can think of at this point. Any additional suggestions would be appreciated. Okay you mite hav ESD something. First take out the RAM an see if you get any beeps from the mother board. If you dont hear any that MEANS the board is bad. If you do it mite be the RAM try useing a differnt one. If that doesn't work the CPU probably died.