Motorola Astro XTL 1500 - Mhz)-Part 2 of 5; RF Power Amplifier (RFPA)-No or Low TX Power Output

June 15, 2005 6815854H01-A
5-38 Troubleshooting Charts: Flowcharts
5.6.27 RF Power Amplifier (RFPA)—No or Low TX Power Output (380–470 MHz and
450–520 MHz)—Part 2 of 5
Figure 5-29. RF Power Amplifier (RFPA)—No or Low TX Power Output (380–470 MHz and 450–520 MHz)—
Part 2 of 5
Defective parts
in matching network
between Q5502 and
Q5503?
(Note 9)
Repair/replace
defective parts
Yes
No
Defective parts
in matching network
between U5501 and
Q5502?
(Note 5)
Repair/replace
defective parts
Yes
Q5502 bias voltages
as per Table 1?
(Note 6)
No
Is Q5502,
gate resistance <
1 MOhms?
(Note 7)
Yes
Repair/replace
Q5502 and retune
gate bias via
Tuner
(see help text)
No
No
Yes
Is Q5502,
drain resistance <
1 MOhms?
(Note 8)
Yes
No
Q5503 bias
voltages as per Table 1?
(Note 10)
Defective parts
in matching network
between Q5503 and
antenna switch?
(Note 13)
Antenna switch
bias voltages as per
Table 1?
(Note 14)
Repair/replace
defective parts
Is Q5503,
gate resistance <
1 MOhms?
(Note 11)
Yes
No
Is Q5503,
drain resistance <
1 MOhms?
(Note 12)
Yes
No
Repair/replace
defective parts
No
No
Yes
Yes
Yes
No
Repair/replace
Q5502 and retune
gate bias via
Tuner
(see help text)
Check/repair/replace
defective parts or
GOTO Power Control
- No/low VGBIAS
Chart
Repair/replace
Q5503
(see General Notes)
and retune gate bias
via Tuner
(see help text)
B
A
Repair/replace
Q5503
(see General Notes)
and retune gate bias
via Tuner
(see help text)
Check/repair/replace
defective parts or
GOTO Power Control
- No/low VGBIAS
Chart