Troubleshooting Charts:
PA Failure
5-63
PA Failure – Page 8 (UHF1 ALC)
Measure voltage at
U1601 pin 1
U1601 pin 1
2.2V +/- 0.6V?
Replace U1601
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
VC_OFFSET low,
remove shield SH10
U1133 pin 6
about 5V?
TX in Current control mode?
U1133 pin 3 4.1V
+/- 0.6?
PA_OFFSET low,
check U1125 pin 1
for approx. 1V, else
replace U1133
R1181 close to 5V?
Measure TP120
No
TP120 1.8V?
No
No
Yes
Check P101 or VOCON
signal DIG_CTRL_IO49
Replace U1139 or
associated logic
Remove shield SH6 and
measure U1142 pin4
U1142 pin 4
1.00V +/- 0.3V?
Measure thermal cutback
circuit output at U1113,
U1114, and U1121
Pin 4 of U1113,
U1114, & U1121
at 0V (logic low)?
Replace log amp, U1105,
else U1112, else check
R1106 for 17 +/- 1 Ohm
Check temp sensor
U1103, else U1148
U1131, pin 4
is 5V?
Replace U1132
No
Yes
TX is in current control mode, else PA is
saturated. Check SAT Reference tuning
per 12M to ensure tuning is not low.
Measure voltage divider
at power tuning DAC, top
of R1121
R1121 around
2.45 V +/- 0.15?
Power tuning is low, else
replace U1125, else U1137,
U1138.
Measure TP101
voltage
TP101
closed to 1.5V?
ANA_CTRL_ISET low. Check R1160
for wrong value, else check connector
P101, or MAKO IC on Vocon
Measure output
pin 4 of U1130
U1101 Pin 1
< 1.3V?
Transmitter PA overcurrent condition,
else check U1101, R1103.
Replace U1129, U1130
Yes
?
U1127 pin 4
approximately
1.10 +/- 0.05V
Replace U1126 and
U1127
Replace U1142
8
Remove shield SH1 & measure
PA control voltage at U1601 pin 4
U1130 pin 4
approximately
1.10 ± 0.05V
Summary of Contents for APX 6000
Page 1: ...APX TWO WAY RADIOS APX 5000 APX 6000 APX 6000XE SRX 2200 Detailed Service Manuals ...
Page 2: ......
Page 6: ...iv Document History Notes ...
Page 20: ...xviii CommercialWarranty Notes ...
Page 26: ...2 4 Radio Power DC Power Routing VOCON Board Notes ...
Page 100: ...3 74 Theory of Operation Bluetooth Notes ...
Page 172: ...5 66 Troubleshooting Charts PA Failure Notes ...
Page 250: ...6 78 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 276: ...7 26 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 300: ...8 24 Schematics Boards Overlays and Parts Lists Transceiver RF Boards VHF Notes ...
Page 336: ...8 60 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF1 Notes ...
Page 378: ...8 102 Schematics Boards Overlays and Parts Lists Transceiver RF Boards 700 800 MHz Notes ...
Page 432: ...Glossary 10 Glossary Notes ...
Page 437: ......