Motorola GP series Service Manual

Chapter 3
TROUBLESHOOTING CHARTS
1.0 Troubleshooting Flow Chart for Receiver (Sheet 1 of 2)
16.8 MHz
at pin 22 U351
?
VCO
locked?
Audio
at pin 27 of
U351?
Bad SINAD
Bad 20dB Quieting
No Recovered Audio
START
Check Controller
Yes
No
Spray of inject 1st IF into
XTAL Filter
IF Freq: 109.65MHz
Audio
heard?
B
Yes
No
Check 2nd LO Control Voltage at C365
B
Yes
Activity
on U351
pin19
?
Check FGU
No
No
A
A
Yes
Check Q350 bias
circuitry for faults.
Rotate Freq. Knob
Check controller
Before replacing U351, check 2nd
VCO Q350. Check VCO O/P level,
C385, C387.
Yes
No

Motorola GP series Specifications

General

Brand	Motorola
Model	GP series
Category	Radio
Language	English