Created by:
Approved by:
Rev.No:
For Stage:
Release Date:
Page: 7 Of 57
Model No: 3420
Drawing No:
Customer :
Model No:
H 520 PLUS
Rev. Date:
TROUBLE SHOOTING HINTS
Symptom
Probable Cause
Remedy
Unit does not work
at all
•
Defective power switch VR601.
•
Empty Battery.
•
Broken wire Battery.
•
Defective D501.
•
Replace
•
Replace
•
Replace
•
Replace
No output from
speaker at all
•
Defective external speaker jack.
•
Wire speaker open.
•
Defective internal speaker.
•
Defective VR601, IC601, Q601 other components.
•
Repair or replace
•
Replace
•
Replace
•
Replace the defective
components.
No noise on
speaker
•
Measure all the voltage of IC601,102 with voltage
chart
•
Defective squelch circuit components (RV101,
VR102, IC102)
•
Replace
•
Replace
Squelch does not
work
•
Defective VR102, RV101, IC102.
•
Replace the defective
components.
•
Re-adjust
No modulation
•
Defective RV702.
•
Defective microphone or EXT microphone jack.
•
Poor audio output and defective modulation
microphone amplifier components (IC103).
•
Defective microphone wire connector.
•
Replace
•
Replace
•
Replace the defective
components.
•
Replace
LCD display does
not work
•
Defective LED.
•
Defective Q803.
•
Replace
•
Replace