TM 11-6625-2638-30
Table 2-3. Test Set Troubleshooting - Continued
STEP
PROCEDURE
NORMAL INDICATION
ABNORMAL INDICATION
CORRECTIVE ACTION
7
Press LAMP TEST switch.
All lamps shall be on.
One or more lamps off (but not all off).
Replace defective lamps.
One or more lamps still off.
Check continuity (para 2-12).
Replace circuit card (para 2-16).
All lamps off except AC and DC POWER.
Check 5 vdc per step 6 a.
Check LAMP TEST switch S14 (para 2-12).
8
Release LAMP TEST switch
All lamps off except AC and DC POWER. TFT lamp may be on or off.
All lamps on.
Check for shorted LAMP TEST switch S14 (para 2-12).
9
Connect return () lead of DVM (DC mode) to J4-h.
10
Measure the power supply voltages at the following connector pins:
4.9 to 5.5 vdc
J3-D
4.9 to 5.5 vdc
RCVR Current + jack
-4.9 to -6.1 vdc
J3-C
13.3 to 14.7 vdc
J4-d
-14.0 to 16.0 vdc
J3-L
19.0 to 25 vdc
J3-K
1 9.0 to -25 vdc
J4-E
26.0 to 30.0 vdc
J1-h
13.0 to 15.0 vdc
J5-b
(DVM to AC mode)
Move DVM Return () to J4-q
26.0 to 34.0 vac
J4-n
26.0 to 34.0 vac
J4-p
One or more voltage is higher than maximum.
Replace power supply (para 2-19).
All voltages missing.
Check relay K1 and interlock S9.
One or more voltages missing but not all.
Check wiring and associated resistor (para 2-12).
Replace power supply (para 2-19).
11
Verify that the RCVR CURRENT switch is in the + 5V position.
Do not let the 5 vdc probe short to anything to prevent damage to power sup-
ply or test set.
12
Connect one end of a test lead with probe to RCVR CURRENT + jack (5 vdc).
2-7
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