Troubleshooting Flow Chart For Receiver - Motorola CDM Series Detailed Service Manual

Section 8: 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
6881091C63-F
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
Yes Check filter between C3474
& C3008. Check tuning
voltage at R3019

Troubleshooting Flow Chart for Receiver

IF signal at Q3102
collector?
No
Check FGU
Check T3001, T3002,
D3031, R3030-R3034,
L3032, C3034 and C3035
Check for 5VDC
present?
No
Check Supply Voltage
circuitry. Check Q0681,
U3211 and U0641
Is tuning Yes
voltage OK?
No
Check U3501
Yes
Before replacing
No
U3101, check
U3101 voltages
Yes
A
No
Yes
Is 9.3V
A
Check varactor filter