Section III. REPAIRS

TM 11-6130-377-14

Figure 6-2. Performance verification and adjustment test setup.

Section III. REPAIRS

the original wiring. For harness cabling, cut the old

6-7.

General Parts Replacement Techniques

conductor as short as possible without removing it from

The procedures required to remove or replace piece

the harness. Dress the new conductor along the

parts and nonrepairable assemblies which are not

harness and spot tie it to the outside of the harness.

obvious or require the removal of one or more parts are

Make connections to same terminals used in the original

given in paragraph 6-7. The following precautions apply

wiring, even where there are alternatives which appear

when removing, replacing, or repairing parts in the

electrically equivalent.

inverter.

a. Before removal or replacement of any part

g. Make well-soldered connections, using no more

unless otherwise stated, remove power from the unit.

solder than is necessary.

A carelessly soldered

Restore power to the unit after the part has been

connection may create a new fault and is one of the

replaced.

most difficult faults to find.

b. Tag all hardware and components during

h. Do not allow drops of solder to fall into the unit.

removal procedures for correct identification during

Do not allow a soldering iron to come into contact with

replacement procedures. Before a part is unsoldered,

insulation or parts that might be injured by excessive

note the position of the leads. If the part has several

heat.

leads, tag each of the leads before unsoldering any of

i. Do not disturb the setting of any uncalibrated

them.

control without redetermining its proper setting before

c. When removing a defective part, be careful not

returning the equipment to service. If any switches are

to damage leads or other parts by pulling or pushing

operated, return them to their original positions.

them out the way.

6-8.

Inverter Repairs

d. When replacing a part, install the new part in the

(fig. 6-1)

same position as the original. Use an exact duplicate

whenever possible.

a. SCR Thyristor A1Q1 (A1Q3) or A1Q2 (A1Q4).

e. Use a pencil-type soldering iron with a 25-watt

(1) Position DC circuit breaker to OFF.

maximum heating capacity. If the iron must be used

(2) Open front indicator panel.

with ac, use an isolating transformer between the iron

(3) Remove twelve screws and lockwashers

and the ac line. Do not use a soldering gun; damaging

securing the top cover and remove the cover.

voltages can be induced in the equipment parts.

f. If wiring must be replaced, use leads of the

same length and gauge if possible. With the exception

of harness cabling, run the leads in the same manner as

Change 1

6-7