iMac G5, 17-inch Take Apart -
Midplane Assembly
7. Locate the optical drive that you set aside. Holding the optical drive by the back end
(near the tab), insert the drive at an angle to mate the two white pins and the plastic
rectangle with the two holes and notch on the optical drive.
8. With your thumb on the tab and your index finger behind the tab, push the drive
forward and down. The optical drive should click into its connector. Note: If the optical
drive won’t click into place, check that the fan cables are not obstructing the optical
drive connector.