ARMY TM 5-6675-238-14
MARINE CORPS TM 08839A-14/1
Table 8-8. Tape Reader Testing and Troubleshooting Procedure - Continued
Malfunction indication
Test procedure
Normal indication
corrective action
NOTE
Any time a component or card is replaced in power supply testing, resistance measurements shall be made (see
figure FO-19, sheet 1) to ensure that a shorted component less than 50 ohms) did not create the failure (if a short is
detected, reverse multimeter test leads to ensure that a diode is not being measured).
2a.
2b.
2c.
2d.
2e.
Connect DVM negative test
DVM indicates +4.5 to + 5.5V
lead to ground (TB2 terminal
10; TP5) and positive test lead
to Al pin 6. (A1 installed on
card extender)
Remove A1 from card ex-
tender and reinstall A1 in card
cage
Connect DVM negative test
DVM indicates +4.5 to + 5.5V
lead to ground (TB2 terminal
10; TP5) and positive test lead
to A2 card cage pin 6 (card
extender must be used; see
note at beginning of test 1)
Connect DVM negative test
DVM indicates +27 to + 29V
lead to ground (TB2 terminal
10; TP5) and positive test lead
to SPOOLING switch S1
common termnal (TP9). See
figure 8-3, sheet L Switch top
terminal
Test results
NOTE
Record results and save for test step 2e.
If OV, continue to step 2e and test Q1,
CR1, and CR2
Same as step 2a
Same as step 2a
NOTE
Steps 2a, 2c, and 2d all failed: Replace
If tests 2a, 2c, and 2d all had nor-
T1
mal indications, test 2 is com-
Steps 2a and 2C both failed: Remove A7
pleted. Proceed as defined in test
and repeat step 2a; if now passes,
1.
replace A7. If still fails, measure less
than 50 ohms (see note at beginning of
test 1) between T1 pin 3 (TP3) and T1
pin 4 (TP4); if good, replace CR2 and
C1. If still fails, check for shorts
Step 2a passed but step 2C failed: Re-
place C3 and AR1
Step 2C passed but step 2a failed: Re-
place A7
Step 2d failed: Go to test step 2f
8-67
