Tait TB8100, Service Manual

Page: 186 / 306

186 Power Amplifier Board Replacement TB8100 Service Manual
© Tait Electronics Limited September 2006
10.5 Replacing the Control Board
Important
You must reprogram and recalibrate the PA after replacing
the control board. Refer to
“Reprogramming and Recal-
ibration” on page 187 .
Refer to “Power Amplifier Disassembly and Reassembly” on page 173 for
details on removing and refitting the cover and front panel, and for screw
torque settings. The circled numbers in the following instructions refer to
Figure 10.5 on page 187 .
Removal
1. Remove the cover and front panel.
2. Remove the ambient air temperature sensor board
b
.
3. Remove the bridging links
c
connecting the board to any adjacent
boards.
4. Desolder the RF links
d
connecting the board to any adjacent
boards. You may need to move the +28V power feed wire
e
out of
the way first.
5. Remove the M3 Torx screws securing the board to the heatsink.
6. Carefully lift the board directly upwards off the locating pins
f
and
remove it from the heatsink.
Refitting 1. To refit the board, follow the removal instructions in reverse order.
Important
When refitting the ambient air temperature sensor board,
make sure that it fits properly into the correct hole provided
in the heatsink (refer to
Figure 10.5 ). You must fit the sen-
sor board in the correct location to ensure that the temper-
ature of the airflow over the sensor is nearest the ambient
temperature of the air from the cooling fan. The sensor
board must not come into contact with the metal of the
heatsink fins. Note that you may feel some resistance as you
push the sensor board through the slot in the foam dust seal
located under the control board.
Note
Before tightening the screws, press the board down over the locat-
ing pins so that it is firmly seated against the heatsink. Then
tighten the M3 Torx screws to the correct torque.