3-128. Replace/Repair Central Processing Unit.
This task covers:
Tool kit, electrician's,
Electrical power to machinery plant
monitoring and alarm system secured
and tagged "Out of Service - Do Not
Data entry keyboard P/N 03-09505-000
Printed circuit board (Z-8)
Printed circuit board (master card)
Printed circuit board (multi-card)
Printed circuit board (power supply)
Warning tags, Item 1, Appendix C
a. Open door (1, Figure 3-115) of enclosure (3).
b. Tag and disconnect electrical leads to central processing unit (CPU) at connections (4).
Remove four hex head bolts (2) securing CPU (5) and enclosure (3) to bulkhead.
d. Remove CPU and enclosure.
e. Remove screws (1, Figure 3-116) and sleeves (2) securing crossbar (3) to
terminal board (10). Remove crossbar (3).
Grasp printed circuit board (multi-card) (5) near the bottom and pull
slightly upward until board is free of connector (4).
g. Slide circuit board straight out until free of upper retaining slide (6).
h. Repeat steps e. through g. for printed circuit boards (7, 12, Z-8), (8, 13,
master card), (9, 14, power supply), and (11, multi-card).
Tag and disconnect electrical leads at terminal strip (15).