Turn it on after unplugging the CD's data cable. If it ejects, then the problem is with the configuration, cable, or motherboard.
Make sure the CDROM is set properly. On most beige G3s, the CDROM was on its own IDE channel and set to Master (most Macs won't do Cable Select, either).
Some later ROM revisions (I think it's Rev. F or something) allow those machines to use two devices on the IDE bus. If that's your case, make sure that one drive is set to Master, the other to Slave.
If it still doesn't work, swap IDE positions on the motherboard (with the hard drive or Zip drive, whichever it is).
Then, change out your cable. Sometimes they can become pinched or something, and quit working.
If all else fails, you might try a SCSI CDROM, if you've got one.
Make sure the CDROM is set properly. On most beige G3s, the CDROM was on its own IDE channel and set to Master (most Macs won't do Cable Select, either).
Some later ROM revisions (I think it's Rev. F or something) allow those machines to use two devices on the IDE bus. If that's your case, make sure that one drive is set to Master, the other to Slave.
If it still doesn't work, swap IDE positions on the motherboard (with the hard drive or Zip drive, whichever it is).
Then, change out your cable. Sometimes they can become pinched or something, and quit working.
If all else fails, you might try a SCSI CDROM, if you've got one.