Motorola Pro3100 Detailed Service Manual

Troubleshooting Flow Chart for 40 W Transmitter Section 13: 3-3
6881091C63-F
2.0 Troubleshooting Flow Chart for 40 W Transmitter
Q5441 gate (63kohm)
and drain resistances
(15kohm)
Check
No
Yes
Is drive from VCO
>+4 dBm?
Is voltage
drop across R5497
between 1 V and 0.7 V
when Tx power
= 44 W?
No
No
Q5421 gate (12kohm)
and drain resistances
(15kohm)
Check
No
PCIC_MOSBIAS_1
Check
No
No
Change
Q5473
START
No power
Is Vctrl
there?
Is Q547
3
OK?
Check voltage
o
n pin 4, U5501
Check voltage
on pin 5, U5501
Check R5422-5
and go back to top
T
roubleshoot
A
SFIC
Change
PCIC
Check R5409 and
R5473 and go back
to top
Check
MOSBIAS_2
/
MOSBIAS_
3
Check
ASFIC
Are D5471
&
D5472 OK?
Change
D5471
&
D5472
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Check
PCIC
Yes
Change Q5421
Change Q5441
Change U5401
Yes
D
o v
i
sua
l
c
h
ec
k
on all components
No
Troubleshoot
VCO
Check voltage
on TP5531
Check if Pressure
Pad closes S5440
Yes

Motorola Pro3100 Specifications

General

Brand	Motorola
Model	Pro3100
Category	Two-Way Radio
Language	English