Motorola GM328

Troubleshooting Flow Chart for 40W Transmitter 3-3
2.0 Troubleshooting Flow Chart for 40W Transmitter (Sheet 1 of 2)
Control Volt-
age at
TP4533
>1V
Current
increase
when
keyed?
NO
YES
START
Check if Pressure Pad closes S5440
Check Components between
Q4441 and RF Output,
Antenna Switch
D4471,D4472,Q4472,
VR4471,Q4471
>500mA & <6A
>6A
<500mA
Check PA Stages
Short TP4531 to
Ground
NO
NO
Voltage at
TP4533
rises?
Check PA Stages
YES
YES
PCIC U4501
Pin 14 9.3V
DC?
Check 9.3 V Regulator
U0641
NO
YES
PCIC U4501
Pin 16 >4V
DC
Replace PCIC U4501
NO
YES
TP4530
9.1V DC
If U4201 Pin 2 is high,
replace PCIC
U4501,otherwise
check controller and
FGU
YES
NO
TP4531
>0.5V DC?
Replace PCIC U4501
Check Forward Power
Sense Circuit (D4451)
Check Forward Power
Sense Circuit (D4451)
NO
YES
PCIC U4501
Pin 5 > 1V
DC?
Check Power Setting,
Tuning & Components
between PCIC Pin 5
and ASFIC (U0221)
Pin 4 before replacing
ASFIC
No or too low Power when keyed
Put in pressure pad
YES
NO
1
Is Q4473
OK?
Change
Q4473
NO
YES
Check voltage
on pin 4
U4501
NO
YES
Check
R4422-5 and
go back to top
1