Tait TP9100 - Page 228

228 Transmitter Fault Finding TP9100 Service Manual
© Tait Electronics Limited May 2005
Task 6 —
Check Temperature
Sensor
If the transmitter is being inhibited and the logic signal at the DTXINH test
point is active, a fault in the temperature sensor might be the cause.
1. Enter the CCTM command 803 to check the temperature reading.
2. Of the two numbers returned, the first is the temperature near the
front panel, and after converting to degrees celsius (use the formula
on page 217) should be about 23 to 25°C. If it is, go to “Biasing of
PA Driver and PA” on page 230. If it is not, go to Step 3.
3. Check D201 and the surrounding components (see Figure 10.5).
The temperature sensor is located on the top side of the main board.
4. If there is no fault, go to “CODEC and Audio ault Finding” on
page 269. If a fault is found, repair it, confirm the removal of the fault
and go to “Final Tasks” on page 134. If the repair failed, replace the
main board and go to “Final Tasks” on page 134.
Figure 10.5 Temperature sensor circuitry (top side)
Temperature sensor circuitry