Service manual

GS160/320 Component Removal and Replacement 4-53
Removal
1. Shut down the operating system(s), put the OCP switch in the Off position,
and trip the main circuit breaker on all AC input boxes.
2. Open the rear door(s).
3. In GS320 systems, skip to step 9.
4. In GS160 systems, remove both the upper and lower QBB faceplates. (See
Section 4.5.)
5. Remove the upper and lower H-switch EMI covers. Unscrew the two
captive screws that hold them in place and remove them.
6. On the left side of the H-switch housing, unscrew the three captive screws
holding the midpanel bracket to the H-switch housing and cabinet.
Remove the bracket and panel.
7. Using a 12 inch Phillips head screwdriver threaded through the cabinet
frame, unscrew the four captive screws holding the H-switch housing on the
right to the cabinet’s inner frame.
8. Swing the H-switch left. Skip step 9.
9. Remove the faceplate on QBB4. (See Section 4.5.)
10. Remove the bottom EMI cover on the right side of the H-switch.
11. The back of the HPM is now exposed. Unscrew the four Phillips head
screws that hold the HPM in place and remove it.
Replacement
Reverse the steps outlined in the removal procedure.
If the HPM firmware on the spare is out of date, choose the appropriate method
to update it. See Appendix D.
Verification
Power up the system and check that the H-switch powers up correctly.
Be sure
to put the circuit breaker in the on position before you put the OCP switch in the On
position. Execute the SRM set sys_serial_num command.