Tait TB8100 Service Manual page 156

Task 1 —
Check Voltage
Levels
12V 28V
12V
28V
Task 2 —
Check Driver
Temperature Sensor
156 Power Amplifier Fault Finding
1. Set up the test equipment as shown in
PA) or Figure 8.9 on page 150
2. Run the Service Kit and connect to the base station.
3. Once connected to the base station, ensure it is in Run Mode.
4. Measure the voltage at pins 2 and 3 of SK101:
For a 12V PA, if the voltage is 28V ±1V, go to
go to Step 5.
For a 28V PA, if the voltage is 28V ±2V, go to
go to Step 6.
5. Measure the voltage at P200 (where the DC supply wire is soldered
to the board). The voltage should be 28V. If it is, replace the 6W
board. If it is not, go to
on page 168.
6. Measure the voltage at the pin of the DC input feedthrough filter.
The voltage should be 28V. If it is, go to
the connection from the power supply to the PA.
7. Check the connection between the pin of the feedthrough filter and
the board. If the connection is not faulty, go to
repair and then go to
8. Measure the voltage at pins 2 and 3 of SK101 again. The voltage
should be 28V. If it is, go to
9. Measure the voltage at TP206 (PIN-BIAS). The voltage should be
between 2V and 2.5V. If it is, go to
6W board.
1. Select Diagnose > Power Amplifier > Control Tests and check that
the driver temperature reading is correct (e.g. if the PA is at ambient
room temperature and not transmitting, the reading on the gauge
should be approximately the same as the ambient temperature). If it
is, go to Task 3. If it is not, go to
2. Remove the links from SK102. Using an oscilloscope, check that
data is present on pin 4 of the control board connector. If it is, replace
the 6W board. If it is not, replace the control board and go to
Figure 8.8 on page 149
(12V PA).
"Boost Regulator Board (12V PA Only)"
Step
Step 8.
Step 9. If it is not, replace the 6W board.
Task 2. If it is not, replace the
Step 2.
© Tait Electronics Limited September 2006
(28V
Step 9. If it is not,
Step 9. If it is not,
7. If it is not, check
Step 8. If it is faulty,
Task 3.
TB8100 Service Manual