IBM 5150 Hardware Maintenance Manual page 275

Power Supply Removal (continued)
5.
If your System Unit contains a Diskette Drive, disconnect the
Diskette Drive power connectors and signal connector( s) (See
Section 5, "Locations"). Reposition the signal cable to allow
the power supply to slide toward the front of the machine.
6. Remove the four power supply mounting screws.
Power Supply
Mounting Screws
(Rear View)
3-100