Realistic TRC-410 - Troubleshooting

6. TROUBLESHOOTING
SYMPTOM
'
CAUSE/REMEDY
A) UNIT WILL NOT
TURN ON.
1.
Defective power switch S3: Replace.
2.
Fuse blown: Replace.
3.
Broken DC power cable: Replace.
4.
Poor solder connection or other open connection in circuit:
Repair or replace.
5.
Defective IC-1: Replace.
B) NO RECEIVE
SOUND.
1.
Defective external Speaker jack: Repair or replace.
2.
Poor contact on microphone connector: Repair as required.
3.
Defective push switch on microphone: Repair or replace MIC.
4.
Defective internal Speaker: Replace Speaker.
5.
Defective D4, VR3, VR2, IC-3 or semiconductor in RX circuit:
Replace the defective component(s).
6.
Defective VR-1: Replace.
C) NO NOISE
1.
Defective Q7: Replace.
2.
Measure transistor & IC voltages in all audio states and receiver
section. Compare with voltages noted on the IC Et TRANSISTOR
VOLTAGE CHART.
3.
Improper local oscillator adjustment: Readjust.
4.
Defective SQUELCH Circuit (IC-3, VR2, VR3): Replace the
defective component(s).
D) NO TRANSMISSION
1.
Defective microphone: Repair or replace microphone.
2.
Defective push switch on microphone: Repair or replace.
3.
Improper adjustment of carrier oscillator or local
oscillator: Readjust.
4.
If you have checked all channels and obtain no RF output, check
V.C.O. and/or signal trace through transmitter circuit.
5.
Defective Antenna connector: Repair or replace.
6.
Defective L1: Repair or replace.
7.
Defective Q14 (E-C short): Replace.
E) NO MODULATION
1.
Defective microphone: Repair or replace microphone.
2.
Poor audio output/Defective modulator: Repair or replace
defective component(s).
3.
Inoperative microphone amplifier (Q13, IC-4): Replace
component(s).
4.
Defective microphone connector: Repair or replace.
5.
Defective AMC circuit (Q11, D7, Q12): Replace component(s).
F) NO SQUELCH
1.
Defective Q7, IC-3 circuit: Replace component(s).
2.
Improper adjustment of VR-3: Readjust.
G) LED METER DOES NOT
OPERATE BUT CB
OPERATES NORMALLY
1.
Defective LED (D11-1 - D11-5): Replace.
2.
Defective IC-5: Replace.
3.
Defective D3, VR-5: Replace.
H) MODULATION
INDICATOR
DOES NOT LIGHT
1.
Defective D15, Q10: Replace.
2.
Check Modulation: Refer E) NO MODULATION.