Troubleshooting - Radio Shack PRO-60 Service Manual

TROUBLESHOOTING
Symptom
Possible Cause/Remedy
Display does not light and no sound comes out
when power is on
Volume control: Maximum (MAX)
Squelch control: Counterclockwise (CCW).
• Defective batteries:
Replace.
• Wrong polarity of batteries:
Correct the polarity of batteries.
• Defective power jack or charge jack:
Replace.
• Defective ON/OFF switch on volume control:
Replace.
Display lights but there is no sound
Volume control: MAX
Squelch control: CCW
• Defective speaker or headphone jack:
Replace.
• Defective audio amplifier circuit (IC306) and/or associated
circuit:
Replace the defective components.
• Defective IF amplifier (IC301) and/or associated circuit:
Replace the defective components.
• Defective squelch control (VR301) and/or associated
circuit:
Replace the defective components.
• Defective AF pre-amp circuit (Q307) and/or associated circuit:
Replace the defective components.
• Defective audio mute switching circuit (Q308) and/or
associated circuit:
Replace the defective components.
• Defective switching circuit (IC303) and/or associated circuit:
Replace the defective components.
Sound comes out but display does not light
Volume control: MAX
Squelch control: CCW
• Defective LCD or rubber connector:
Replace the defective components.
• Defective CPU (IC1):
Replace IC1.
Does not scan and squelch does not operate
• Defective IC301 or IC302 squelch control terminal:
Replace IC301 or IC302.
Does not scan but squelch operates
• Defective CPU (IC1):
Replace IC1.
Shows correct display at the time of
programming, but after scanning, shows faulty
display
• Defective CPU (IC1) and/or associated circuit:
Replace the defective components.
Sound does not come out in NFM mode but
AM and WFM operate
• Defective 1C 1:
Replace.
• Defective control circuit (IC303, IC305) and/or associated
circuit:
Replace the defective components.
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