Circuit Board Removal and Replacement

TM 11-7010-201-40-5/ET821-AA-MMI-050/E154 MTS/T O 31S5-2TSQ73-2-5

5-14. Circuit Board Removal and Replacement. (See figure 5-1.) The circuit board (8) may be removed and replaced

by performing the following procedures.

a. Removal. Perform the following procedure to remove the circuit board (8).

(1) Remove six screws (3) securing access cover (2) to chassis (1) and remove access cover (2).

NOTE

Some external wiring connections to pins of circuit board (8) are terminated by connectors or wire wrap.

The connectors slide off the circuit board pins and do not require a special removal tool. Wire wrap

connections must be unwrapped using Gardner/Denver unwrapping tool model 515665-26 or equivalent.

(2) Tag and remove connecting wires from circuit board (8).

(3) Loosen three knurled captive screws securing front panel (17) to chassis (1) and open front panel (17).

(4) Tag, unsolder, and remove wires from VCC lug and three ground lugs on circuit board (8).

(5) Loosen and remove four screws (9) and washers (10) securing circuit board (8) to top of hexagonal spacers

(11).

(6) Remove circuit board (8).

b. Replacement. Perform the following procedure to replace the circuit board (8).

(1) Install circuit board (8) to top of hexagonal spacers (11), and secure with four screws (9) and washers (10).

(2) Install and solder wires to VCC lug and three ground lugs, as tagged, on circuit board (8).

NOTE

Installation of wire wrap connectors does not require a special tool. Wire wrap connections must be

wrapped using Gardner-Denver wire wrap tool models 14B1 or 14R, or equivalent, with bit number

506445 and sleeve number 507100 or equivalent. That portion of a wire that has been unwrapped shall

not be used again. If there is sufficient unused wire, as from a service loop, the wire may be cut,

restripped, and a new wrap termination made. If necessary, replace wire.

(3) Install wires, as tagged, to circuit board (8).

(4) Close front panel (17), and secure to chassis (1) with three knurled captive screws.

(5) Install access cover (2) on chassis (1), and secure with six screws (3).

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