Exchanging the power distribution board in the 5088 and 0588 expansion units

Use this procedure to remove or replace the power distribution board (PB1).

1. Remove the top, front, and rear covers (see Exchanging the covers in the 5088 and 0588 expansion units).
2. Power off the expansion unit (see Powering off an expansion unit). Pull the power plugs that run from the unit to the ac box of the lower unit.
3. Remove the center top plate.
4. Remove the two power supplies (see Exchanging the power supplies in the 5088 and 0588 expansion units).
5. From the top of the unit, remove and label the cables that connect to the power distribution board.
6. Remove the screws that secure the power distribution board to the expansion unit.
7. Pull the power distribution board out through the top of the expansion unit.
8. Install the new power distribution backplane by reversing this procedure.
9. After exchanging an item, go to Verifying the repair. This ends the procedure.