Tait TM8100 mobiles Service Manual page 368

Task 17 —
Shaper and
Level Shifter
368 Transmitter Fault Finding (25W)
If the voltage measured in
second PA or the shaper and level shifter for the PA is suspect.
Important
Ensure that the current limit on the DC supply is 2A.
And, when entering the CCTM command 332 y, do not
specify a value y higher than that recorded in
Failure to do so might result in the destruction of the PAs.
1. If the can has already been removed, go to
PAF TOP
go to Step 2.
Enter the CCTM command 32 to place the radio in receive mode.
2.
3. Remove the
PAF TOP
Enter the CCTM command 33 to place the radio in transmit mode.
4.
5. Enter the CCTM command 332 y (where y was recorded in
6. Check that the voltage at the gate of Q309 is (see
gate of Q309: 2 to 5V
Enter the CCTM command 32 to place the radio in receive mode.
7.
8. If the voltage is correct, Q309 is faulty; replace the board and go to
"Final Tasks" on page
9. Check the circuitry between pin 8 of IC301 and the gate of Q309
(see Figure 12.9). If a fault is found, repair it, confirm the removal
of the fault, and go to
or Q309 itself is faulty, replace the board and go to
page 163.
Task 16 is correct but not the current, either the
can.
163. If it is not, go to
"Final Tasks" on page
© Tait Electronics Limited November 2007
Task 12.
Step 5. If it has not,
Task 12).
Figure 12.9):
Step 9.
163. If the repair failed
"Final Tasks" on
TM8100/TM8200 Service Manual