I have an old Dell Dimension 8300 computer I'm using for the time being while I wait for my power supply to come in on Tuesday. I took out the CD-drive and the DVD-drive and put it in my new build. Now, the old Dell will not start. I made sure everything was plugged into the hard drive and motherboard. It all checks out good. Am missing something? Power to the CPU, CPU fan, 20 pin motherboard connector, and hard drive are all in place. The computer will boot and I get a screen that says no drive found. It worked ten minutes ago before I pulled the optical drives out.
It's all about the Dell BIOS settings. Dell sets their machines up to run with a specific hardware config and any changes from that will cause it to do what it's (not) doing to you. If you can get into the BIOS, just change the appropriate boot order and (if any) stop POST settings.
Its possible that the first boot device set in the bios is the CD Drive, and now that its gone it may be making the system stop rather than looking for the next device. Usually that doesn't happen, however its a possibility. Also it could be that the Hard drive was sharing the PATA cable with the CD-drive and you may need to check the jumper settings or position of the drive on the cable. If the jumper on the drive is Cable Select make sure that the drive is at the end of the ribbon cable, if that doesn't work and the drive is on the cable alone move the jumper to the Master position ( or if there are 2 drives make sure the one at the end of the cable is set to master and the other one is set to slave, or both to cable select). I don't know if this will help or not, but its worth a look anyhow. Good Luck!