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TM 55-4920-412-13&P
p.
Analog Processor No. 1 Assembly (A9). Shift
Reg Drive and reset from (A6) and ANA PROC No. 2
Circuits.
(1)
Connect test equipment as shown in
Figure 4-1, unit tester connected. Set Power to OFF and
remove Analog Processor Board on extender board.
Insert extender board into unit tester.
(2)
Place INTER CAL SELECT switch to 21.
Connect digital voltmeter leads between test loops 4 (+)
and 118 (-). Set Power to ON. Digital voltmeter will
indicate between 4.5 and 5.5 vdc. If not, see
troubleshooting table 4-34.
(3)
Set Power to OFF. Disconnect digital
voltmeter leads from unit tester.
(4)
Set
Power
to
OFF
and
connect
oscilloscope between test loops 54 (HI) and 118 (LO).
Set power to ON. Oscilloscope will display positive-
going square wave pulses 4.5 to 5.0 V p-p. If not, see
troubleshooting table 4-34.
(5)
Set power to OFF. Disconnect from test
loop 54.
(6)
Connect oscilloscope to test loop 38 and
set
power
to
ON.
Oscilloscope
will
display
approximately
10
micro
seconds
reset
pulse
momentarily as indicated when Inter Face Monitor is
resetting. If not, see troubleshooting table 4-34.
(7)
Set
power
to
OFF
and
disconnect
oscilloscope
from
test
loop
38
and
reconnect
oscilloscope to test loop 42.
(8)
Set power to ON. Oscilloscope will
display positive going pulse, 4.5 to 5.5 V p-p. If not, see
troubleshooting table 4-34.
(9)
Set
power
OFF
and
disconnect
oscilloscope from test loop 42 and reconnect to 22.
(10)
Set power to ON. Oscilloscope will
display positive going pulses 4.5 to 5.5 V p-p. Observe
oscilloscope DC level shifting from ground to +5 v with
Interface Monitor count between 950 and 1000, shifting
back from ground when Interface Monitor resets to zero.
If not, see troubleshooting table 4-34.
Table 4-34. Troubleshooting Analog Processor Board No. 1 (A9), Shift Reg Drive and Reset, Ana Proc No. 2
Trouble
Probable Cause
Remedy
5 vdc low or missing
Logic Power Supply A3. INPUT 8V
Replace defective components or
missing to Regulator Board (A4) or
Regulator Board (A4). See figs. 4-13,
Output 5V missing. Analog Proces-
4-14, 4-21, FO-6, FO-7, FO-8, FO-13.
sor #2 (A10).
Shift Reg Drive has incorrect Input
Inter Cal Select switch, interwiring
Replace defective components or re-
from Board (A6)
Board. OSC Board (A6). Analog
place board (A6). See figs. 4-14, 4-16,
Processor No. 2 (A10).
4-21, FO-6, FO-8, FO-10, FO-13.
Shift Reg Reset input missing from
Inter Cal Select switch, interwiring
Replace defective components or re-
Board (A6)
Board. OSC Board (A6). Analog
place board (A6). See figs. 4-16, 4-21,
Processor No. 2 (A10)
FO-6, FO-10, FO-13.
ANA PROC No 2 Output incorrect
Analog Processor No. 1 (A9). OSC
Replace defective components or re-
Board (A6).
place boards (A6), (A9). See figs.
4-16, 4-22, FO-10, FO-14.
4-64
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