Troubleshooting Flow Chart For Receiver - Motorola GM328 Service Manual

3-2
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
1.1
B
Inject RF into J3401
IF Signal at
C3035?
No
RF Signal at
T3001?
No
RF Signal at
C3012?
No
RF Signal at
C3008?
No or
weak RF
RF Signal at
C3474?
No
Check Harmonic Filter
J3401 and
Antenna Switch
D3471,D3472,L3472
Trace IF signal from
Yes
C3035 to Q3101.
Check for bad XTAL
filter
1st
Yes
LO level OK?
Locked?
Yes
Yes
Check filter between
C3012 & T3001
Yes
Check RF amp
(Q3001) Stage
Check filter between C3474
Yes
& C3008. Check tuning
voltage at R3019
IF signal at Q3102
No
Check FGU
Check T3001, T3002,
D3031, R3030-R3034,
L3032, C3034 and C3035
Check for 5VDC
Is 9V3 present?
Check Supply Voltage
circuitry. Check Q0681,
U3211 and U0641
Is tuning
voltage OK?
No
Check U3501

Troubleshooting Flow Chart for Receiver

Yes
collector?
Before replacing
No
U3101, check
U3101 voltages
Yes
No
Yes
No
Yes
Check varactor filter
A
A