7. Install the new hard disk drive fan assembly by aligning the rubber mounts of the fan assembly with theholes in the hard disk drive fan assembly bracket and pushing the rubber mounts through the holes.8. Connect the hard disk drive fan assembly cable to the system board, and then install the bracket andhard disk drive fan assembly to the chassis.9. Go to “Completing the FRU replacement” on page 106.Replacing an optical driveAttentionDo not open your computer or attempt any repair before reading and understanding the “Important safety information”in the ThinkStation Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkStationSafety and Warranty Guide, go to:http://www.lenovo.com/support.This section provides instructions on how to replace an optical drive.1. Remove the computer cover. See “Removing the cover” on page 76.2. Remove the front bezel. See “Removing the front bezel” on page 80.3. Locate the optical drive. See “Locations” on page 77.4. Note the location of the optical drive cables. Disconnect the signal and power cables from the rear ofthe optical drive.5. Press the drive latch 1 (for the drive you want to remove) and slide the optical drive from the chassis.Chapter 11. Replacing FRUs (Type 4155, 4158, 4218) 129