Motorola APX 6000 Service Manual

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
NoNo
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

Motorola APX 6000 Specifications

General

Frequency Range	700/800 MHz, VHF, UHF Range 1, UHF Range 2
IP Rating	IP67
P25 Phase 1 & 2	Yes
GPS	Yes
Encryption	AES, DES
Power Output	1-3 Watts (700/800 MHz)
Operating Temperature	-30°C to +60°C
Intrinsically Safe	Yes
Bluetooth	Yes (Bluetooth 4.0)