Motorola GP series Detailed Service Manual

2-2 TROUBLESHOOTING CHARTS
2.0 Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
Check Q210, U201
(pin 48) voltages
and U247
Check harmonic filters
L101 & L102
CR101, CR102
and CR300
Is R5
present
?
RF
Signal
at C317
?
Trace IF signal
from L353 to
U352. Check for
bad XTAL filter.
IF
Signal
at L353
?
No
RF
Signal at
pin8U301
?
No
Are
the AGC
voltages without
RF as indi-
cated
?
RF
Signal
at C301
?
Inject RF into J101
RF
Signal at
the input
of FL300
?
Check RF amp
(Q301) Stage.
Replace filter
FL301.
Yes
Check U301, R320,
R321, R322
Yes
1st LO O/P
OK?
Locked?
Yes
Check FGU
Yes
No
Yes
Is
the level of
the IF signal of the
output of U352 as
indicated
?
Yes
Is
the biasing
of U352 OK
?
No
No
No
Check U302,
U350 and
CR301.
No
Yes
Yes
A
B
Before replacing
U351, check
U351 voltages;
trace IF signal
path.
Replace
U352
No or
weak
RF
Yes
Replace
U352
No or
weak
RF

Motorola GP series Specifications

General

Brand	Motorola
Model	GP series
Category	Radio
Language	English