|
| |
TM 55-4920-412-13&P
(20)
Set Power Switch to ON. Oscilloscope
will display a rectangular pulse 4.5 to 5.5 Vp-p.
Frequency counter will indicate between 126 and 130
kHz.
If
not,
see
Troubleshooting
Table
4-32.
Disconnect oscilloscope and frequency counter after
setting power to OFF.
(21)
Connect digital multimeter leads between
J9 pin 19 and COM (P/S Control Normal).
(22)
Adjust P/S Control fully CW and set Power
Switch to ON.
Table 4-32. Troubleshooting Oscillator Board (A6) Circuits
Trouble
Probable Cause
Remedy
Shift Register Drive-pulses incor-
Analog Set Switch (S15). Oscillator
Replace defective components or re-
rect when ANALOG set to SLOW
board (A6).
place board (A6) if required. See
or FAST
figs. 4-16, FO-6. FO-10.
Shift Register, 183 O/P pulses in-
Analog Set Switch (S15). Analogue
Replace defective components or re-
correct
Processor Board No. 2 (A10).
place boards (A6)(A10) if required.
Oscillator board (A6).
See figs. 4-16, 4-21, FO-6, FO-10, FO-13.
ANA-DIG UPDATE pulses incor-
Analogue Set switch (S 15).
Replace defective components or re-
rect (continuous)
Oscillator board (A6).
place board (A6) if required. See
figs. 4-16, FO-6, FO-10.
INTERNAL CLOCK OUTPUT and
Inter Cal Select Switch (S6). Oscilla-
Replace defective components or re-
display pulses incorrect
tor board (A6). B C D Counter
place boards (A6XA5) if required.
Board (A5).
See figs. 4-16, 4-18, FO-6, FO-10,
FO-11.
10 vdc, -10 vdc, + vdc (Input)
Voltage Regulator Board (A4).
Replace Regulator Board (A4). See
Low or missing
figs. 4-14, FO-8.
TEST FREQ-puleas incorrect
Oscillator board (A6).
Replace defective components orre-
place board (A6) if required. See
figs. 4-16, FO-10.
DIGITAL DISPLAY UPDATE-
Inter Cal Select switch (S6). Oscilla-
Replace defective components orreplace
display pulses incorrect
tor Board (A6).
board (A6). See figs 4-16, FO-4, FO-10.
DIGITAL DISPLAY CLOCK IN-
Inter Cal Select switch (S6). Oscilla-
Replace defective components or re-
HIBIT pulses and Freq incorrect
tor board (A6).
place board (A6). See figs. 4-16,
FO-6, FO-10.
RESET PULSE missing
Oscillator board (A6). Analog
Replace defective components or re-
Processor No. 2 (A10) Board.
place boards (A6) (A10) if required.
See figs. 4-16, 4-21, FO-10, FO-13.
P/S CONTROL AUTO-DIM voltage
Regulator Board (A4).
Replace defective components or re-
low or missing
place board (A4). See figs. 4-14,
FO-8.
P/S LAMP SENSE incorrect volt-
Lamp Power Supply (A2).
Replace defective components or re-
age low or missing
place board (A2) if required. See figs.
4-15, FO-9.
Change 2 4-59
|
