Table-3-2. Troubleshooting Data

TM 11-6125-259-30

Table-3-2. Troubleshooting Data

MALFUNCTION

PROBABLE CAUSE

CORRECTIVE ACTION

Inverter input terminals pins A and C of

Transistor Q206, Q207, Q208, Q306,

J1 shorted

Replace defective component, or defective

Q307, Q308, Q200 through Q205 and

A2 (A3 module)

Q300 through Q305; diode CR200

through CR205 and CR3OO through

CR305 shorted.

Replace defective component, or defective

Inverter will not turn on (no output

Transistor Q500 through Q505, Q605;

A5/A6 module,

diode CR510 through CR519, integrated

voltage).

circuit Z608 defective.

Inverter draws excessive input current.

Capacitor C400, C401A and/or C401B

Replace defective A4 module.

defective,

No output voltage regulation at no-load.

Diode CR206, CR207, CR306 and CR307

Replace defective component, or defective

A2/A3/A7 modules.

open; Transistor Q206, Q207, Q208, Q306,

Q307, Q308, Q700 and Q701 open; in-

tegrated circuit Z700, Z702 and Z703

defective.

Check set-in test calibration for potentio-

Poor output voltage regulation at full

Replace defective component, or defective

meters R732 and R742; diodes CR520

load.

A7/A5 module.

through CR523; integrated circuit Z703

defective.

Transistor Q600, Q601, Q602 and Q603;

Output frequency drifts with input

Replace defective component, or defective

diode CR600 and CR601 defective.

A6 module.

voltage change.

Check set-in-test calibration for resistors

Output frequency out-of-tolerance.

Replace defective component, or defective

A6 module.

R607 and R608; integrated circuit Z600

defective.

Replace defective A5 module.

Capacitor C500 and C505, or C501 and

High distortion for any one of the three

C504 or C502 and C503; Choke L500,

phases.

L501 and L502 defective.

RepIace defective component, or defective

Transistor Q200 through Q205, Q300

High distortion for all three phases.

A2/A3/A4/A6 module.

through Q305, Q400 through Q411; in-

tegrated circuit Z603, Z607 through Z611

defective.

Low efficiency.

Replace defective component, or defective

Transistor Q200 through Q205, Q300

A2/A3/A4 module.

through Q305, Q400 through Q411

defective.

Replace defective component, or defective

Insufficient overload capacity.

Diodes CR200 through CR205, CR300

A2/A3 module.

through CR305 defective.

b. Remove top cover (1) by removing 34 screws (3)

3-9. (Complete Disassembly of Inverter

and 34 flat washers (2).

Perform only as much of this procedure as necessary

c. Remove rear cover (9) by removing three

to remove or test the suspected defective assembly

screws (3) and three washers (2); and removing four

or component. Be sure no power is applied to in-

screws (3), four lockwashers (7) and four flat washers

verter during disassembly.

(2).

NOTE

d. Remove Al module (33) by removing three

Use normal shop practice of unsoldering

screws (3) and three flat washers (2); and removing

(or unscrewing wire terminal) and tagging

four screws (32), four lockwashers (7) and four flat

(identifying) all interconnecting wires

washers (2).

that must be detached to disassemble

e. Remove A5 module (34) by removing two

inverter. During assembly the tagged

screws (32), two lockwashers (7) and two flat

information will enable wires to be

washers (2); and removing two screws (8), two

soldered back in place or the wire ter-

lockwashers (7), two flat washers (2) and two cable

minal to be screwed back into proper

clamps (4 and 6).

location.

f. Remove A4 module (5) by removing four screws

a. Remove bottom cover (14, fig. 3-21) by

(8), four lockwashers (7), four flat washers (2) and

four cable clamps (4 and 6).

removing six screws (19).

3-19