Motorola GM338

Troubleshooting Flow Chart for 40W Transmitter 3-3
2.0 Troubleshooting Flow Chart for 40W Transmitter
No
Is Q4441 OK ?
Yes
Is drive from VCO
>+4dBm?
No
Is voltage drop across
R4497 >4.5V ?
No
Check Q4431 gate(open)
and drain resistances
(11kohm)
No
Check Q4421 gate(open)
and drain resistances
(11kohm)
No
Check
PCIC_MOSBIAS_1
No
No
Change
Q4573
START
No power
Is Vctrl
there?
Is Q4573
OK?
Check voltage
on pin 4 U4501
Check voltage
on pin 5 U4501
Check R4422-5
and go back to top
Troubleshoot
ASFIC
Check voltage
on TP4531
Change
PCIC
Check R4409 &
R4473 and go back
to top
Check
MOSBIAS_2
Check
ASFIC
Are D4471 &
D4472 OK?
Change
D4471 &
D4472
No
NoNo
No No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Check
PCIC
Yes
Change Q4421
Change Q4431
Yes
Change U4401
Yes
Do visual check
on all components
No
Change Q4441
Troubleshoot
VCO