IBM B50 - Manual (Page 151)

Power Supply
DANGER
Do not attempt to open the covers of the power supply. Power supplies
are not servicable and are to be replaced as a unit.
Removal
1. Remove the cover as described in “Removing the Cover” on page 7-3.
2. Remove the riser card support bracket, as described in “Riser Card Support
Bracket” on page 7-10.
3. Disconnect the power supply cables from the system board connectors and any
installed drives. Label each cable, identifying where it connects.
4. Remove the mounting screws from the rear of the power supply.
5. Remove the power supply from the system by moving it forward and then
upward, as shown in the following illustration:
Replacement
Replace in reverse order, noting the following power supply cable attachments.
System board power cables
Diskette drive power cable
Disk drive power cables
Media drive power cables
Chapter 7. Removal and Replacement Procedures 7-7