Replacement of Logic Circuit Card Assembly A79A1

TM 9-1240-369-34

KEY to fig. 3-4:

(4) Remove the logic circuit card assembly.

1. Screw--NAS163-06-6

(5) Install new logic circuit card assembly by

2. Washer--NAS620C6L

performing steps (2) thru (4) in reverse order.

3. Access cover--11738817

(6) Install access cover as instructed in

4. Screw locking assembly--11739036

paragraph 3-9 a steps (2) and (3).

c. RepIacement of Readout Circuit Assembly A79A2

5. Connector A1P1--M24308/3-4

(see fig. 3-4).

6. Screw--NAS1635-04-4

7. Screw--NAS1352-04-4

(1) Remove access cover as instructed in

8. Washer-AN960C4

paragraph 3-9 a step (1).

9. Logic circuit card assembly A79A1-11737334

(2) Remove screw (10), three screws (11), four

10. Screw--NAS1635-04-4

washers (12) and readout circuit assembly A79A2 (13).

11. Screw--NAS1352-04-4

(3) Loosen two screws on screw locking

12. Washer--NAS620C4

assembly (14) and disconnect harness connector W1P1

13. Readout circuit assembly A79A2-11737350

(15) from connector A2J 1 on readout circuit assembly

14. Screw locking assembly--11739036

A79A2 (13).

15. Connector W1P1--M24308/1-3

(4) Install new readout circuit assembly A79A2

16. Screw--MS3213-7

(13) by performing steps (2) and (3) in reverse order.

17. Lens bracket--11737330

(5) Install access cover as instructed in

18. Lens gasket--11737331

paragraph 3-9a step (2) and (3).

19. Filter lens--1737329

d. Replacement of Lens Gasket and Lens Filter (see

20. Insert-MS21209C0415.

fig. 3-4).

21. Switch lens seal--11745629

(1) Remove access cover as instructed in

22. Switch lens--11741527-1

paragraph 3-9 a step (1).

23. Switch lens--11741527-2

(2) Remove readout circuit assembly A79A2 as

21. Switch lens--11741527-3

described in paragraph 3-9 c.

25. Seal adapter--11737385

(3) Remove eight screws (16), lens bracket (17)

26. Lockwasher--part of item 28

lens gasket (18), and filter lens (19). Inspect screws.

27. Key washer--part of item 28

washers and inserts (20) for damage and replace as

28. Switch S4 thru S6--11745600

necessary.

29. Preformed packing--NAS1523AA7Y

(4) Before installing lens gasket, lubricate by

33. Lamp--11738097

applying thin uniform film of grease, MIL-G-4343. Apply by

31. Nut--part of items 28 thru 32

hand to both surfaces of the lens gasket.

32. Lockwasher-MS35338-138

(5) Install new lens gasket or filter lens by

33. Indicator light DA5--11737364-1

performing steps (2) and (3) in the reverse order.

34. Indicator light DS4--11737364-2

(6) Reinstall access cover as instructed in

35. Indicator light DS6--11737364-3

paragraph 3-9a steps (2) and (3).

36. Indicator light DS8--11737364-5

e. RepIacement of RANGE RETURN SELECTOR

37. Indicator light DS7--11737364-4

switches S4 thru S6 and Switch Lens Seals (21) (see fig. 3-

38. Preformed packing--MS28775-009

4). The following steps are applicable to each indicator S4

39. Switch lens seal--11737499-1

thru S6 and its switch lens seal (21).

40. Seal adapter--10737544

(1) Remove access cover as instructed in

41. Lockwasher--part of items 39 or 40

paragraph 3-9 a step (1).

42. Key washer--11745580

(2) Unscrew applicable switch lens seal (21) from

43. Preformed packing--NAS1523AA7Y

housing with boot removal tool (21, table 2-2).

44. DMR switch S1--MIL-S-8805/99-004

(3) Pull applicable switch lens (22, 23 or 24)

45. TSW switch S2--MIL-S-8805/99-032

straight out from housing.

46. Housing--11738815

(4) Tag all leads to applicable switch for

b. Replacement of Logic Circuit Card Assembly

identification. Unsolder leads.

A79A1 (see fig.3-4).

(5) Remove applicable seal adapter (25)

(1) Remove access cover as instructed in

lockwasher (26), key washer (27), switch S4 thru S6 (28)

paragraph 3-9 a step (1).

and preformed packing (29) from housing.

(2) Remove three screws (6), three screws

(6) Lubricate preformed packing (29) by applying

(7), and six washers (8) that secure the logic circuit card

a thin, uniform, film of grease, MIL-G-4343.

assembly (9) to housing.

(7) Install new switch lens seal and switch by

(3) Loosen two screws on screw locking

performing steps (1) thru (5) in reverse order. Install switch

assembly (4) and disconnect connector A1P1 (5) from

lens seal with boot removal tool (21, table 2-2).

harness connector W1J1.

3-13