TM 55-4920-413-13&P
d. Torque NO 1 and NO 2.
(1) Set ON-OFF-SIM ONLY switch to OFF.
(2) Connect digital voltmeter to T1 connector NO 1 pins
E (HI) and F (LOW), using two leads (B7). Refer to Figure 4-2
for pin locations.
(3) Set TORQUE NO 1 CAL/NOR switch to CAL and
HI/LO switch to HI.
(4) Set ON-OFF-SIM ONLY switch to SIM ONLY. Dig-
ital voltmeter will indicate between 3.6 and 3.8 vdc. If not, per-
form Troubleshooting Table 4-7.
(5) Set TORQUE NO 1 HI/LO switch to LO. Digital volt-
meter will indicate between -0.1 and +0.1 vdc. If not, perform
Troubleshooting Table 4-7.
(6) Set TORQUE NO 1 CAL/NOR switch to NOR and
turn variable control fully CCW. Digital voltmeter will indicate
between –0.1 and +0.1 vdc. If not, perform Troubleshooting
Table 4-7.
(7) Adjust variable control fully CW. Digital voltmeter
will indicate 5.415 vdc minimum. If not, perform Troubleshoot-
ing Table 4-7.
(8) Set ON-OFF-SIM ONLY switch to OFF.
(9) Disconnect leads from connector NO 1 pins E (HI)
and F (LOW) and connect to connector NO 2 pins a (HI) and
b (LOW).
(10) Repeat (3) thru (8) above, except use TORQUE NO
2 controls.
Table 4-7. Troubleshooting Torque NO 1 or NO 2 (AVIM).
NOTE
Before troubleshooting, remove DC simulator A4 board and reconnect using extender board.
Trouble
Probable Cause
Remedy
Torque
C11, C12, R52, CR5 (6.2 vdc), also
First check loops 18 (+) and 14 (-)
No HI-CAL VOLTAGE
NO 1 (R45)
for input 12 vdc ±5 vdc, Replace
NO 2 (R48)
defective components, Figure 4-6,
4-7, FO-2, FO-5 or replace A4 board.
HI-CAL VOLTAGE
Trim Resistors
Use decade resistor box, and check
Indication out of tolerance
NO 1 – (R46, R51)
or replace malfunctioning
NO 2 – (R49, R50)
components, Figures 4-6,4-7, FO-2,
FO-5 or replace A4 board.
HI-CAL VOLTAGE
NO 1 – CR5, R44, R45, S34 or S35,
If trim resistors do not bring
Indication out of tolerance after trim
NO 2 – CR5, R48, R47, S36, or S37
reading in tolerance replace mal-
resistors checked or replaced
functioning components, Figures 4-5,
4-7, FO-2, FO-6 or replace A4 board.
LO-CAL Indication out
NO 1 – (S34)
Replace malfunctioning components,
of tolerance
NO 2 – (S35)
Figures 4-6,4-7, FO-2, FO-5 or
replace A4 board.
Indication out of tolerance in
NO 1 (R16)
Replace malfunctioning components,
NOR-FULLY GCW
NO 2 (R17)
Figures 4-6,4-7, FO-2, FO-5 or
replace A4 board.
In NOR-FULLY CW
NO 1 (R16) (R44)
Replace malfunctioning component,
NO 2 (R17) (R47)
Figures 4-6,4-7, FO-2, FO-5 or
replace A4 board.
NOTE
Voltage checks are also listed on figure 4-7.
4-12
