Tait TB8100 - Page 161

TB8100 Service Manual Power Amplifier Fault Finding 161
© Tait Electronics Limited September 2006
4. Measure the resistance of the termination resistor to ground. It
should be 50Ω . If it is, the splitter board is not faulty. Proceed to
“60W Board” on page 162. If it is not, proceed as follows:
■ if the resistor is SMD, replace the splitter board
■ if the resistor is mounted on the heatsink, replace the resistor and
repeat the test (refer to “Replacing the Splitter/Combiner
Boards” on page 190).
Task 2 —
Check the Combiner
Board
1. Check the DC continuity from port 1 to the output, and from port 2
to the termination resistor. If there is continuity, go to Step 3. If
there is not, go to Step 2.
2. Check for faulty solder joints between the combiner and the PCB. If
the solder joints are not faulty, replace the combiner board. If there
is a faulty joint, repair as necessary and repeat Step 1. If there is still
no continuity, replace the combiner board.
3. Check that there is no DC short to ground on each of the four ports.
If there is a short, replace the combiner board. If there is not, go to
Step 4.
4. Measure the resistance of the termination resistor to ground. It
should be 50Ω. If it is, the combiner board is not faulty. Proceed to
“60W Board” on page 162. If it is not, replace the termination
resistor and repeat the test (refer to “Replacing the Splitter/
Combiner Boards” on page 190).