Troubleshooting Flow Chart For 40W Transmitter - Motorola GM328 Service Manual

Troubleshooting Flow Chart for 40W Transmitter

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