b. CENTRAL PROCESSING UNIT Circuit Board Removal.
Special precautions are necessary when handling static-sensitive
components such as the CPU and peripheral devices. Irreparable
damage can be caused by touching an input lead, especially when done
in a low humidity environment. The following points should be followed
to minimize the possibilities of damage. All ac-test equipment used, in
addition to surrounding electrical apparatus, should be grounded in
accordance with National Electrical Code Standards, as well as local
codes. All work surfaces should be covered with copper or aluminum
and grounded by use of a strap or braid to a solid earth ground. All
personnel working on the equipment should be grounded to the work
surface by means of a metallic wrist strap in series with a one-megohm
Turn off the power to the SFD.
Remove the rear cover, following the instructions in paragraph 3-6a(2),
Remove the two screws in the front of the interface board.
(4) Disconnect ribbon connectors P11 and P12. Hinge back the interface
board and disconnect P1, P2, and P3 where they plug into the CPU Board. Observe
the same precautions as for removing the connectors on the interface board.
(5) Remove the six 1/4-inch nuts securing the circuit board to the chassis.
Lift out the board. Reassemble by reversing the above procedure.
c. Front Panel Circuit Board Removal.
Turn off power to the SFD.
Remove the two screws on each side of the SFD near the front.
Remove the decorative knobs from the collimator-shutter-slide controls.
(4) Lift the rear of the front-panel assembly approximately 1/2-inch (13mm),
while sliding it to the rear. Lift out the assembly.
(5) Disconnect all ribbon cables and headers. Observe the same
precautions as for removing the connectors on the interface and CPU boards.
(6) Remove the 10 screws holding the board in place. Lift out the circuit
board. Reassemble by reversing the above procedure.