TM 11-6625-3053-14
ITEM
MALFUNCTION
CHECKS/CORRECTIVE ACTION
6
b) Remove high voltage cover if on (para 6-22).
(cont'd)
c) Set multimeter to 1000 VDC range.
d)
Set sig gen initial settings of para 2-4.
e) Energize sig gen and multimeter.
f)
Wait 2 mins and set MODULATION Switch to CW.
g) Using multimeter, check voltage between chassis ground and test
pin 12 on A2A1 card assy. Voltage should read -325 VDC.
If voltage is not obtained, go to T/S item 7.
If voltage is obtained, go to check 2 below.
2. Check -425V output from A2A1 card assy.
a) Using multimeter as set, measure voltage between test pin 12
and test pin 5 on the A2A1 card assy.
Voltage should be -425VDC.
If voltage obtained, check wiring between test pin 5 on A2A1 card
and -750V test point on tracking board assy. Repair as required.
If voltage not obtained, go to check 3 below.
3. Rectifier output check.
a) Using multimeter, set to 1000 VDC range and measure voltage
between test pin 12 and junction of C1 and R12 on A2A1 card
assy.
Voltage should be greater than -495 VDC.
If voltage is not obtained, go to check 4 below.
If voltage is obtained, check R12 and CR5. Replace faulty
component.
If this does not correct the -425 output, go to check 5 below.
4. Input check.
a) Using multimeter, set to 1000 VAC range. Measure voltage
across test pins 1 and 2 on A2A1 card assy.
Voltage should be approx 593 VAC.
If voltage not obtained, go to troubleshooting item 8.
If voltage obtained, check CR1 through CR4 and replace
defective component.
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