To Remove The 300/600 Megabyte Fixed Disk Drive Expansion Unit; To Replace The Expansion Unit - Compaq PORTABLE 386 Maintenance And Service Manual

9. Remove the retaining screw that secures each optional expansion board to
the expansion unit.
on the circuit board (Figure 8-105).
To replace the expansion unit, reverse steps 1 through 9.
Chapter 8.30 300/600 Megabyte Fixed Disk Drive Expansion Unit
Gently lift the board(s) up and out of its connector