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

Troubleshooting Flow Chart for 40W Transmitter

2.0

Troubleshooting Flow Chart for 40W Transmitter

No
Is Q5573
OK?
Change
Yes
Q4573
Yes
Check voltage
n U5501, pin 4
Check R5422-5
No
and go back to top
No
Check voltage
on U5501, pin 5
Troubleshoot
ASFIC
Yes
No
Check voltage
on TP5531
Change
PCIC
Yes
Check R5409 and
R5473 and go back
to top
Change Q5441
START
No power
No
Is Vctrl
there?
Change Q5431
No
Check Q5431 gate(open)
and drain resistances
(11kohm)
Yes
Is Q5441 OK ?
No
Is voltage drop across
R5497 >4.5V ?
Change U5401
Yes
Check
MOSBIAS_2
Yes
Check
PCIC_MOSBIAS_1
Yes
Are D5471 &
D5472 OK?
Yes
Yes
Check Q5421 gate(open)
and drain resistances
(11kohm)
No
Yes
Is drive from VCO
>+4dBm?
No
No
Check
ASFIC
No Check
PCIC
No
Change
D5471 &
D5472
No
Change Q5421
Troubleshoot
VCO
Yes
Do visual check
on all components
3-3