348
Transmitter Fault Finding (25W Radios)
TM9100 Service Manual
© Tait Electronics Limited
August 2005
Task 21 —
Check Power
Control
Check the power-control circuitry if the clamp current for the PA driver is
correct or if the voltage at the
SET
PWR
test point is incorrect.
Important
Ensure that the current limit on the DC supply is 2A.
And, when entering the CCTM command
304 z
, do not
specify a value
z
higher than that recorded in
Task 12
. Fail-
ure to do so might result in the destruction of the PA driver.
1.
Enter the CCTM command
304 z
(where
z
was recorded in
Task 12
).
2.
Note the current reading on the DC power supply.
3.
Enter the CCTM command
114 0
to switch off the power.
4.
Note the current reading on the DC power supply.
5.
Compare the above current readings. The current should decrease by
an amount approximately equal to the offset given in
Table 12.6
.
If it does, go to
Task 25
in
“RF Signal Path” on page 355
. If it does
not, go to
Step 6
.
6.
Check that the voltage from the DAC is changing. Measure the
voltage at the
PWR
test point
(
CDC
TX
PWR
CTL
) (see
Figure 12.9
).
7.
Enter the CCTM command
114 1023
. The voltage should increase
to:
8.
Enter the CCTM command
32
to place the radio in receive mode.
9.
If the voltage at the
PWR
test point
increases as required, go to
Task 22
. If it does not, go to
“CODEC and Audio Fault Finding” on
page 371
.
PWR test point: 2.4
±
0.1V
Summary of Contents for TM9100
Page 1: ...TM9100 mobiles Service Manual MMA 00017 01 Issue 1 August 2005 ...
Page 4: ...4 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 10: ...10 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 22: ...22 Introduction TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 62: ...62 Description TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 96: ...96 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 138: ...138 Disassembly and Reassembly TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 152: ...152 Servicing Procedures TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 168: ...168 Interface Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 244: ...244 Receiver Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 396: ...396 CODEC and Audio Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 420: ...420 Fault Finding of Control Head TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 426: ...426 Spare Parts TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 430: ...430 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 444: ...444 TMAA04 05 Ignition Sense Kit TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 448: ...448 TMAA10 01 Desktop Microphone TM9100 Service Manual Tait Electronics Limited August 2005 ...