IBM 6643 - Manual (Page 35)

To remove the power supply, do the following:
1. Disconnect the power cable.
2. Remove the two base cover wings and the upper base cover from the hinge
stand assembly, see “Upper base cover and base cover wing removal” on page
22.
3. Remove the rear EMC cover assembly, see “Rear EMC cover assembly
removal” on page 23.
4. Disconnect the hard disk drive power cable.
5. Disconnect the diskette drive power cable.
6. Disconnect the power supply cable from the system board.
7. Remove the USB card from the top of the power supply (two screws).
8. Remove the cable retainer on top of the hinge stand assembly.
9. Remove the power supply screws.
10. Lift the power supply up and out of the chassis.
Chapter 4. FRU replacements 27