Repair and Replacement 11-11
Replacing Parts
Replacing an AC Power Supply
BPX switches are powered by redundant power supplies; either power supply can supply the current
requirements of the node. The AC Power Supply is part of an assembly which is replaced as a single
unit. Access to the AC Power Supply assembly is from the front, but first, the Air Intake Grille must
be removed.
To remove a power supply, proceed as follows:
Step 1 If you haven't already done so, check the status and output voltage of the power supplies
at the node using the dspasm command. Note which power supply is failed, A or B.
Power supply A is on the right side facing the rear of the node.
Step 2 Remove the Air Intake Grille. Locate the small access hole in the top, center of the Air
Intake Grille.
Step 3 Fully insert a flat-bladed screwdriver (with a 1/4 in. blade) in the access hole.
Step 4 Rotate the screwdriver to release the spring latch holding the Air Intake Grille
(see Figure 11-4). The grille should pop out.
Figure 11-4 AC Power Supply Assembly
Step 5 Tilt the grille forward approximately a 45 angle, then lift if out and set it aside. This
exposes the power supply retainer bracket.
Step 6 With a flat-bladed screwdriver, loosen the retainer bracket hold-down screw in the center
of the bracket and tilt the bracket.
Step 7 Identify which power supply needs replacement. Power supply A is the unit on the left, B
is on the right. In most cases, the failed unit will be identified by a front panel lamp
indication.
SLOT A
SLOT B
Power supply
thumb screw
Power supply
retainer
Retainer
captive
screw
H8212
Slot B empty if
non-redundant
Power
supply
Power supply
plunger hole
Plunger
Power supply
thumb screw
