Replacement of Electronic Component Assembly A78A2 and Circuit Card Assemblies A78A3

TM 9-1240-369-34

KEY to fig. 3-3:

(1) Remove access (cover as instructed in

paragraph 3-7 a.

Screw--MS51957-30

Washer-NAS620C6L

(2) Remove screws (8), four washers (9), and

Access cover--11737865

four battery retainers (10).

Gasket- 11638849

Power control electronic component assembly

WARNING

A78A2--11738850

The storage battery assembly A78B1

Battery charge sensor circuit card assembly

can supply enough short circuit

A78A3--11738808

current to generate temperatures

Charge control circuit card assembly A78A4--

high enough to cause metal to fuse

11738818

together, and also cause severe

Screw--MS51957-46

burns to the human body. When

Washer--NAS620C8

handling the battery assembly,

10. Battery retainer--11737834

remove all rings from fingers and do

11. Storage battery assembly--11737972

not insert metal objects into the

12. Housing assembly--11738845

immediate area of the battery

assembly.

b. Replacement

Electronic

Component

(3) Disconnect battery leads from storage

Assembly A78A2 and Circuit Card Assemblies A78A3

battery assembly terminal and lift out.

and A78A4 (see, fig. 3-3).

(1) Remove access cover as instructed in

CAUTION

paragraph 3-7 a step (1).

When installing replacement storage

battery

assembly,

ensure

that

WARNING

terminal on the black battery lead is

The

power

control

electronic

connected to the negative terminal of

component assembly (5) is adjacent

A78B1, and the red battery lead is

to the terminals on the storage

connected to the positive terminal of

battery assembly (11). The storage

A78B1.

battery assembly can supply enough

(4) Install replacement storage battery

short circuit current to generate

assembly by performing steps (1) thru (3) in reverse

temperature high enough to cause

order.

metal to fuse together, and also

cause severe burns to the human

3-8. Inspection of Battery Power Supply Unit (A78)

body. Remove all rings from fingers

a. Inspect the general condition of all parts. Check

and do not insert metal objects into

for wear or other conditions indicating deterioration.

immediate area of the battery

b. Inspect storage battery assembly, battery pack

assembly.

retainer, and screws for corrosion. Check gasket for

(2) Remove the desired electronic component

deterioration and machined surfaces for conditions that

assembly (5) or circuit card assembly (6 or 7). No

might prevent alinement with mating parts.

special instructions are required for removal or

c. Check electrical wiring for chafed or broken

replacement.

wires and bad solder connections.

(3) Install new assemblies by performing

d. Charge batteries in battery power supply unit and

steps (1) and (2) in reverse order.

verify condition before replacing with new parts.

c. Replacement of Storage Battery Assembly

e. Inspect machined sealing surfaces for scratches.

A78B1 (see fig. 3-3.

debris or excessive lubricant that may prevent proper

sealing.

Section V. REPAIR OF LASER RANGING COMMANDER'S CONTROL

C-9134/VVG-1 (A79)

that the disassembled items be indexed in order of

3-9. Disassembly of Commander's Control Unit

removal.

Assembly can then be accomplished by

(A79).

replacing items in reverse index order. After any repair,

The commander's control unit is to be disassembled only

the commander's control unit must be purged with dry

to the point where the damaged items can be removed

nitrogen gas in accordance with TM 9-2350-230-12.

and replaced. During disassembly, it is recommended

3-9