TM 55-4920-410-13&P
4-11. Troubleshooting and Repair (ATST).
a. Paras 4-11 and 4-12 contain general information for
troubleshooting. Test equipment and accessories are
listed in Tables 4-3 and 4-4. Refer to FO-1 for the test set
schematic diagram and Fig C-3 for the electrical compo-
nent assembly. Troubleshooting procedures are listed in
tables 4-7 and 4-8. The adapter cable wiring diagram is Fig
4-7. See troubleshooting tables as applicable before
proceeding with performance checks.
b. Extender board, Bendix, P/N 1106610-1 is required
for troubleshooting circuit boards and is listed in table 4-4.
4-12. Analyzer Circuit Checks.
a. GEN/PMG VOLTS Meter.
(1) Set all test switches to down or OFF.
(2) Set GEN/PMG VOLTS switches to T1.
(3) Pull 400 GEN-T1, T2, and T3 circuit breakers
to out position.
(4) Connect test equipment as shown in Figure 4-2
(DC power supply not connected).
(5) Set AC power supply to ON and adjust for l15V
output at 400 Hz.
(6) Push 400 GEN-T1 circuit breaker to IN posi-
tion. Observe test set for a 115V indication on GEN/PMG
Volts meter. If not, see troubleshooting Table 4-7.
(7’) Pull 400 GEN-T1 circuit breaker to OUT posi-
tion and disconnect lead from pin A of J1 and connect to
pin B of J1.
(8) Set GEN/PMG VOLTS switch to T2 and repeat
(3) thru (7) above, except use 400 GEN-T2 circuit breaker.
(9) Disconnect lead from pin B of J1 and connect to
pin C of J1.
(10) Set GEN/PMG VOLTS switch to T3 and repeat
(3) thru (6) above, except use 400 GEN-T3 circuit breaker.
(11) Disconnect test equiment from test set.
b. FREQUENCY METER Circuit.
(1) Connect test equipment as shown in Figure 4-2
(DC power supply not connected) with test set power
OFF.
(2) Set all test switches to down or OFF.
(3) Set GEN/PMG VOLTS switches to T1.
(4) Pull 400 GEN-T1 circuit breaker to
position.
OUT
(5) Press 400 GEN-T1 circuit breaker to IN
position.
4-4
(6) Adjust AC power supply for 400 Hz indication
on FREQUENCY METER. If not, see troubleshooting
Table 4-7.
(7) Disconnect test equipment from test set.
c. PMG Volts Meter and 1200 Hz Power Circuit.
(1) Pull PMG AØ, BØ, and CØ circuit breakers to
OUT positions and set GEN/PMG VOLTS switch to AB.
(2) Connect equipment as shown in Figure 4-3 and
set all test switches to down or OFF.
(3) Adjust AC power supply for 21 vac at 1200 HZ
and push PMG AØ and BØ circuit breakers to IN posi-
sitions.
(4) GEN/PMG Volts meter will indicate approxi-
mately 21 vat. If not, see troubleshooting Table 4-7.
(5) Pull PMG AØ and BØ circuit breakers to OUT
positions.
(6) Connect test lead to J1 connector pin X (+) and
w (–) to the digital voltmeter.
(7) Push PMG AØ and BØ circuit breakers to IN
positions.
(8) Digital voltmeter will indicate approximately
27.5 vdc. If not, perform troubleshooting Table 4-7.
(9) Pull PMG AØ and BØ circuit breakers to OUT
positions.
(10) Disconnect lead from pin D of J1 and connect to
pin F of J1 and set GEN/PMG VOLTS switch to BC and
push PMG BØ and CØ circuit breakers to IN positions.
(11) Repeat technique (8) above.
(12) Pull PMG BØ and CØ circuit breakers to OUT
positions.
(13) Disconnect lead from pin E of J1 and connect to
pin D of J1.
(14) Set GEN/PMG VOLTS switch to CA and push
PMG CØ and AØ circuit breakers to IN positions.
(15) Repeat technique (8) above.
(16) Disconnect test equipment from test set and set
all test switches to down or OFF.
d. 400 Hz Power Supply Circuit.
(1) Pull 400 Hz GEN T-1 circuit breaker to OUT
position and set GEN/PMG VOLTS switch to T1. Observe
that all other test switches are down or OFF.
(2) Connect test quipment as shown in Figure 4-2
(DC power supply not connected) with digital voltmeter
leads between J1 connector pins X (+) and w (–).
