Motorola CDM Series Detailed Service Manual page 620

Section 12: 3-4
Troubleshooting Flow Chart for 40 W Transmitter (Sheet 2 of 2)
2.1
6881091C63-F
Check PA Stages
Change
Q4441
NO
Check Q4441
gate (63kohm) YES
and drain
resistances
(15kohm)
YES
YES
Is drive from
Is voltage drop
VCO
across R4497
>+4dBm?
>4.5V?
NO
Change
Troubleshoot
U4401
VCO
Troubleshooting Flow Chart for 40 W Transmitter
1
Check
NO
Check
MOSBIAS_2/
ASFIC
MOSBIAS_3
YES
Check
NO
Check
PCIC_MOS
PCIC
BIAS_1
YES
Change
NO
D4471 &
Are D4471 &
D4472
D4472 OK?
YES
Check Q4421
NO
gate (12kohm) Change
and drain Q4421
resistances
(15kohm)
YES
Do visual check on
all components
NO