TM 55-4920-413-13&P
(7) Set ON-OFF-SIM ONLY switch to OFF and precision
oscillator switch to OFF.
(8) Connect equipment as shown in Figure 4-10, connec-
tion A, for connector NO 2.
(9) Repeat (2) through (4) above except use ENGINE OIL
PRESS NO 2 controls. If not within tolerance in (4) above, per-
form (4) (a) through (c) and (a) below. If not in tolerance in (6)
above, perform (4) (a) through (c) above and 9 (b) and (c) below.
(a) Adjust R22 (figure 4-11) for a 3.591 vac indica-
tions on digital voltmeter.
m. XMSN Oil Press.
(1) Connect equipment as shown in Figure 4-10, connec-
tion B, for connector NO 2. Do not disconnect equipment con-
nected in Figure 4-1.
(2) Set XMSN OIL PRESS CAL/NOR switch to CAL
and HI/LO switch to LO.
(3) Set precision oscillator (A6) is 6.00 Vrms at 400
+/- 10Hz.
(4) Set ON-OFF-SIM ONLY switch to SIM ONLY. If
digital voltmeter does not indicate between 3.447 and 3.735
vat, perform (a) through (d) below. If still defective, per-
(b) Turn ENGINE OIL PRESSURE NO 2 varia-
form Troubleshooting Table 4-16.
ble control fully CCW.
(a) Set autotransformer, dc power supply, and
precision oscillator power to OFF.
(c) Adjust R18 (fig 4-11) for a 3.591 vac indication on
(b) Remove pressure board
digital voltmeter.
reinstall, using extender board (B4).
A2 (Figure 4-11) and
Table 4-16. Troubleshooting XMSN OIL PRESS (AVIM).
NOTE
Before performing troubleshooting, remove frequency simulator A2 board and reconnect using extender board,
Trouble
Probable Cause
Remedy
LO/NOR Fully CW
R39
First check loops 5 (+) and 14(-) for
indication out of tolerance
15 vdc ±5 vdc. Then loop 3 for -15
vdc. If voltages are present proceed
below. Replace defective compo-
nents, Fig-m-es 4-11, 4-12, FO-4,
FO-5, or replace A2 board.
LO/NOR Fully CW
R13, R39, R38, U3, L1, or S2/S3
Replace defective components,
indication out of tolerance after
(Front Panel)
Figures 4-11, 4-12, FO-4, FO-5, or
adjustment (R39)
replace A2 board.
LO/NOR Fully CCW
R35
Replace defective components,
indication out of tolerance
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
LO/NOR Fully CCW
R35, R1
Replace defective components,
indication out of tolerance
Figures 4-11, 4-12, FO-4, FO-5, or
after adjustment (R35)
replace A2 board.
LO/CAL
R43
Replace defective components,
indication out of tolerance
NO 2 (R26)
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
LO/CAL indication out of
HI/LOW switch R42 R36,
Replace defective components,
tolerance after adjustment (R43)
C15, C16, Cl?, U4, U3
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
LO/CAL indication out of
HI/LOW switch R42, R36
Replace defective components,
tolerance after adjustment (R43)
C15, C16, C17, U4, U3
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
HI/CAL indication out of
R41
Replace defective components,
tolerance
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
HI/CAL indication out of
R40 or R37
Replace defective components,
tolerance after adjustment (R41)
U3
Figures 4-11, 4-12, FO-4, FO-5, or
replace A2 board.
NOTE
Check input voltage to (A2) board from (A1) board before troubleshooting (A2) board. Voltage checks are listed in Table
4-17, using figure 4-10 connections.
Change 1
4-27