Motorola APX 6000 Service Manual

Troubleshooting Charts: PA Failure 5-61
PA Failure – Page 6 (7/800 ALC)
Measure voltage at U1001 pin 1
U1001 pin 1
2.2V +/- 0.3V?
Replace U1001
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
VC_OFFSET low,
remove SH12
U1133 pin 6
about 5V?
TX in Current control mode?
U1133 pin 3 4.5V
+/- 0.5?
PA_OFFSET low,
check U1125 pin 1
for approx. 1V, else
replace U1133
R1181 5V?
Measure TP120
No
TP120 1.8V?
No
Yes
Check P101 or VOCON
signal DIG_CTRL_IO49
Replace U1139 or
associated logic
Remove SH11 and
measure U1142 pin4
U1142 pin 4
1.15V +/- 0.01V?
Measure thermal cutback circuit
output at U1113, U1114, and U1121
Yes
No
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
1.15V +/- 0.015?
Power tuning is low, else
replace U1125, else U1137,
U1138.
Measure TP101 voltage
TP101 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
U1130 pin 4
approximately
1.15v?
U1101 Pin 1
< 1.3V?
U1127 pin 4
approximately
1.15V?
Transmitter PA overcurrent condition,
else check U1101, R1103.
Replace U1129, U1130
Replace U1142
Replace U1127,
else U1126
6
Remove SH9A & measure
PA control voltage at U1001 pin 4

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)