Removal and Replacement of the Display and Control Circuit Card Assembly A6A1

TM 11-5895-1179-13 E132-EA-OMP-010/E106 KY883 TO 31S1-2GGSC-161

-12, and -13 (figure 5-2). Disconnect the fan assembly leads at A7TBl-9 and -11.

Disconnect the four backplane harness assembly leads connected to A5AlTBl on the backplane circuit card

assembly (figures 5-4 and 5-6). Disconnect the interconnect cable assembly A8A3 from A5A1J8 on the

backplane circuit card assembly.

Remove the six screws and washers (figure 5-4) which attach the rear panel assembly to the chassis

assembly and remove the rear panel assembly A5 with the backplane circuit card assembly A5A1 mounted

to it.

Remove the ten backplane circuit card assembly mounting screws, flat washers and lock washers (figures

5-4 and 5-6). Separate the backplane circuit card assembly from the rear panel assembly. The keying bracket

A5MP1 will fall from the assembly.

Loosen the card guide on the replacement backplane circuit card assembly by loosening the two mounting

Insert the four plug-in-circuit card assemblies into the chassis assembly.

Fit the backplane circuit card assembly over the four plug-in circuit card assemblies and tighten the two

screws holding the card guide to the backplane circuit card assembly (figure 5-6).

Position the backplane circuit card assembly A5A1 on the rear panel assembly A5; position the keying

bracket A5MP1 removed in step I on A5A1 and initially insert the two longer screws with flat washers and

lock washers, loosely, to hold the rear panel assembly, backplane circuit card assembly, and keying bracket

together. Insert the remaining 8 screws with flat and lock washers to secure A5A1 to the rear panel

assembly. Tighten the ten screws.

Position the rear panel assembly on the chassis and secure it in place with the six screws removed in step e.

Remove the four plug-in-circuit card assemblies.

Connect the four backplane harness assembly leads removed in step I to A5AlTB1 on the backplane

assembly and the three power connector assembly and two fan assembly leads removed in step to A7TB1

on the bottom panel assembly. Reconnect the interconnect cable assembly A8A3 removed in step A to

A5A1J8 on the backplane circuit card assembly.

Install the jam nuts removed in step h. Install lockwireMS20995C-20, item 4, App. E, as shown in figure 5-4.

Install the four plug-in-circuit card assemblies (paragraph 4-7) and the chassis cover (paragraph 5-6).

Close and secure the front panel assembly.

Reconnect cables to A5A1J5, A5A1J6, A5A1J7, and A5J13 (figure 2-2).

5-15.

Removal and Replacement of the Display and Control Circuit Card Assembly A6A1

Remove the nuts and washers from all the front panel assembly toggle switches except the ON/OFF switch

(figure 5-3). Loosen the set screws on the FUNCTION select switch knob, the ENCODER

5-17