Motorola CDM Series Detailed Service Manual page 245

Troubleshooting Flow Chart for 25 W Transmitter
2.0 Troubleshooting Flow Chart for 25 W Transmitter (Sheet 1 of 3)
Check Components between
Q4441 and RF Output,
Antenna Switch
D4471,D4472,Q4472,
VR3471,Q3471
Check PA Stages
Check 9.3 V Regulator
U0641
Replace PCIC U4501
If U4201 Pin 2 is high,
replace PCIC
U4501,otherwise
check controller and
FGU
Check Power Setting,
Tuning & Components
between PCIC Pin 5
and ASFIC (U0221)
Pin 4 before replacing
ASFIC
Replace PCIC U4501
START
No power or low power when keyed
Check if Pressure Pad closes S5440
Current
>500mA & <4A
>4A
increase
when
keyed?
<500mA
Control
YES
Voltage at
TP4402
>1V
NO
NO PCIC U4501
Pin 14 9.3V
DC?
YES
NO
PCIC U4501
Pin 16 >4V
DC
YES
NO
TP4404
9.1V DC
YES
NO
PCIC U4501
Pin 5 > 1V
DC?
YES
YES
TP4403
>0.5V DC?
NO
Check Forward Power
Sense Circuit (D4451)
Short TP4403 to
NO
Check PA Stages
Check Forward Power
Sense Circuit (D4451)
Section 5: 3-3
Ground
Voltage at
TP4402
rises?
YES
6881091C63-F