Tait TM8100 mobiles, Service Manual

Page: 355 / 620

TM8100/TM8200 Service Manual Transmitter Fault Finding (25W) 355
© Tait Electronics Limited November 2007
12. Repair any fault, confirm the removal of the fault, and go to “Final
Tasks” on page 163 . If the repair failed or no fault could be found,
replace the board and go to “Final Tasks” on page 163 .
Task 8 —
Check Temperature
Sensor
If the transmitter is being inhibited and the logic signal at the
D TX INH
test
point is active, a fault in the temperature sensor might be the cause.
1. Enter the CCTM command
47
to check the temperature reading.
2. Of the two numbers returned, the first is the temperature in degrees
celsius and should be about 25°C. If it is, go to
Task 12 in “Biasing of
PA Driver and PAs” on page 360 . If it is not, go to Step 3 .
3. If not already done, remove the
PAF TOP
can.
4. Check D301 and the surrounding components — see Figure 12.6 .
5. If there is no fault, go to “CODEC and Audio Fault Finding” on
page 399 . If a fault is found, repair it, confirm the removal of the
fault, and go to “Final Tasks” on page 163 . If the repair failed, replace
the board and go to “Final Tasks” on page 163 .