Realistic PRO-2021 - Troubleshooting; Display and Audio Problems; Scanning and Squelch Malfunctions

TROUBLESHOOTING
1) Display does not light and no 1) Faulty power cord:
sound when POWER is on. е Replace the power cord.
Volume Contro! : MAX. 2) Defective power transformer:
Squelch Control е Replace the power transformer.
Counterclockwise (CCW) 3) Defective power switch:
е Replace the Volume control (VR-2).
4) Defective rectifier D43:
@ Replace the D43.
5) Defective voltage regulator circuit components:
€ Replace the defective parts.
1) Defective speaker or headphone jack:
o Repiace the defective parts.
2) Defective audio amplifier ІС-9 and/or associated circuit components:
е Replace the defective parts.
3) Defective IF amplifier ІС-2 and/or associated circuit components:
е Repiace the defective parts.
4) Defective functional squelch control IC-3, IC-5 and/or associated circuit
components:
€ Replace the defective parts.
2) Display lights but no sound.
Volume Control : MAX.
Squelch Control : CCW
1) 1С-11 is running “wild”:
€ Activate Reset Switch.
2) Defective initiate control and/or associated circuit components:
* Replace the defective parts.
3) Defective IC-4 and/or associated circuit components:
е Replace the defective parts.
4) Defective DC-DC converter circuit components:
* Replace the defective parts.
5) Defective LCD:
@ Replace.
6) Defective CPU IC-11 and/or associated circuit components:
@ Repiace the defective parts.
7) Defective 018, 19, D26 and/or associated circuit components:
е Replace the defective parts.
8) Defective EL1 and/or associated circuit components:
@ Replace the defective parts.
3) Sound but display does not light.
Volume Control : MAX.
Squelch Control : CCW
1) Defective functional squelch control ІС-5, 017 and/or associated circuit
components:
е Replace the defective parts.
2) Defective ІС-2 and/or associated circuit components:
@ Replace the defective parts.
3) Defective IC-4 and/or associated circuit components:
е Replace the defective parts.
4) Does not scan and squelch does not
operate.
5) Does not scan but saueich operates. 1) Defective 017, IC-5 and/or associated circuit components:
@ Replace the defective parts.
2) IC-11 is running “wild”:
e Replace Reset Switch.
3) Defective ІС-11 and/or associated circuit components:
е Replace the defective parts.
Squeich control is not adjusted correctly:
e Adjust SOUELCH (VR-1) clockwise.
6) Scan does not operate but
MANUAL selector operates.
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