Motorola GM328 Service Manual page 296

3-2
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
1.1
B
Inject RF into J1401
IF Signal at
pin 2 of
U1051
No
RF Signal
at pin 3 of
U1051?
No
RF Signal at
C1017?
No
RF Signal at
C1013?
No or
weak RF
RF Signal at
C1002?
No
Check harmonic filters J1401 and ant.switch
Trace IF signal from
Yes
C1036 to Q1106.
Check for bad
XTAL filter.
Yes
No
1st LO level
OK?
Locked?
Yes
Yes
Check filter between C1017
& mixer U1051
Yes
Check RF amp (Q1001)
Stage.
Yes
Check preselector and RF
amp.
Troubleshooting Flow Chart for Receiver (Sheet 1 of 2)
Check FGU
Check for detailed mixer.
IF signal at
Yes
Q1106 collec-
tor?
Before replacing
U1103, check
U1103 voltages.
No
Yes
Is 9V3 present?
No
Check Supply Voltage cir-
cuitry. Check U0681,
U3211 and U0641.
A