IBM 6643 - Manual (Page 39)

Chassis assembly 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.
7. Remove the two screws as shown.
8. Pull the chassis assembly forward, then up to remove it from the LCD housing
assembly.
Chapter 4. FRU replacements 31