IBM 6643 - Manual (Page 37)

System board removal
1. Remove the rear bucket housing, see “Rear bucket housing (rear cover)
removal” on page 21.
2. Remove the rear EMC cover assembly, see “Rear EMC cover assembly
removal” on page 23.
3. Disconnect all cables attached to the system board.
4. Unplug any installed PCI cards.
5. Remove the nine system board screws.
6. Lift the system board from the chassis assembly.
Power inverter board removal
Attention:
1. Unplug the power cord from the computer before servicing the Power inverter board.
2. Do not power on the computer unless the power inverter board cover with insulator is
properly installed.
Chapter 4. FRU replacements 29