TM 11-6625-1831-13
5-3b.
Troubleshooting Test Panel (Cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
45. MT OUT J8 display not correct.
Step 1.
Check TARGET CLUTTER potentiometer R7, TARGET LEVEL potentiometer R6, and
BASELINE CLUTTER potentiometer R8. Remove Oscillator and Switch Module 1A2
Measure resistance through R7, R6 and R8 from XA2. Check resistance with knobs at
minimum and maximum settings. See schematic for pin numbers and values
Repair wiring or replace potentiometer as needed (para 5-14, 5-6).
Step 2.
Check Oscillator and Switch Module 1A2 by replacing it.
Install new module (para 5-6).
46. Doppler sine wave not correct.
Step 1.
Check FREQ potentiometers R3A and R3B. Remove Oscillator and Switch Module 1A2
Measure resistance through R3A from XA2-5 to TB1-5, and R3B from XA2-5 to TB1-7 Each
reading should change from 0 to 2500 ohms as the knob is turned
Replace defective potentiometer (para 5-6).
Step 1.
Check Oscillator and Switch Module 1A2 by replacing it.
Install new module (para 5-6).
47. Doppler sine wave not correct.
Step 1.
Check BASELINE CLUTTER potentiometer R8 and TARGET LEVEL potentiometer R6
Remove Oscillator and Switch Module 1A2. Measure resistance through R8 and R6 at XA2
See schematic for pin numbers and values.
Replace defective potentiometer (para 5-6).
Step 2.
Check Oscillator and Switch Module 1A2 by replacing it.
Install new module (para 5-6).
48. High frequency display is not present during trigger output (only)
Check Oscillator and Switch Module 1A2 by replacing it.
Install new module (para 5-6).
49.+5 volts not present at ECCM LEVEL jack.
Step 1.
Check wiring. Test for open circuit between ECCM LEVEL jack and ECCM Circuit Card
1A6-E8. Test for open circuit between +5 volt line at XA3-V and 1A6-E11
Repair as necessary (para 5-14).
Step 2.
Check ECCM Circuit Card 1A6 by replacing it.
Install new card (para 5-6).
50. Voltage at ECCM LEVEL jack is not 0.0 Vdc.
Check LEVEL 1 switch S16 by replacing it.
Install new switch (para 5-6).
5-37
Previous Page
