Motorola ASTRO XTS 5000 - Page 129

November 16, 2006 6881094C31-E
5-38 Troubleshooting Charts: TX RF (VHF and UHF Range 2)
TX RF (VHF and UHF Range 2)—Page 3
INT > 5 Vdc?
Vgate at TP111
is low (< 4 Vdc)
Measure INT
at TP104
Yes
No
No
Yes
Yes
No
Replace
Q108
INT is low.
Measure VLIM
at TP119
PCIC is
programmed.
Measure TEMP
at R124
Bad PCIC
Replace U104
VLIM
about 2 to
3 Vdc?
No
Yes
Measure
RFIN at
TP101
TEMP
< 1.0 Vdc at
25C?
RFIN is low, INT
is low, bad PCIC,
replace U104
TP101
< 0.5 Vdc?
Low output power,
RFIN is high, check
RF detectors and
op amp U106.
Repair defects
Repair temperatur
e
sensor circuit
(U103, Q109,
R130)
4
4
TXINH
< 1 Vdc?
TX7V is low.
Measure TXINH
at P1-19, Q101-b
No
No
Yes
Yes
RXH
< 1 Vdc?
No
Yes
Bad PCIC
Replace U104
RXH
> 5 Vdc?
Bad control
signal from
VOCON
Trace dc levels
through switching
transistors Q101,
Q102, Q103,
and Q106
Replace bad
transistors
Measure RXH
at U104-23
and Q103-b
3
MAEPF-27476-A