TM9100 Service Manual
CODEC and Audio Fault Finding
383
© Tait Electronics Limited
August 2005
Task 8 —
Check Signal
from CODEC
First generate an appropriate audio test signal and check whether the signal
is present at the output of the CODEC circuitry.
1.
Enter the CCTM command
400 x
, where
x
is a valid channel number.
(A suitable channel will depend on the programming of the radio.)
2.
Enter the CCTM command
21
to force unmuting of the received
audio signal.
3.
Enter the CCTM command
110 128
to set the audio level at its
midpoint.
4.
At the test set apply 60%, 1 kHz modulation to the RF signal. Reduce
the volume to a minimum.
5.
Enter the CCTM command
324 r5
.
6.
Check that the received signal is present at pin 2 (
AUD TAP OUT
) of the
internal-options connector SK102 (see
Figure 13.5
) (alternatively,
the measurement point for
CDC
AUD
TAP
OUT
shown in
Figure 13.4
).
The signal should be:
7.
If the above signal is correct, go to
Step 8
. If it is not, go to
Task 9
.
8.
Check the components in the path from pin 13 of the auxiliary
connector SK101 to the CODEC and audio circuitry. These are
C719
and L708 (see
Figure 13.6
) and the link R747
(see
Figure 13.5
). Also check the auxiliary connector itself. Repair
any fault.
9.
Confirm the removal of the fault and go to
Step 10
. If the repair failed
or the fault could not be found, replace the main-board assembly and
go to
“Final Tasks” on page 147
.
10.
If there is also a fault with the transmit modulation, notwithstanding
modulation at the auxiliary connector, go to
Task 15
of
“Faulty
Modulation Using Auxiliary Connector” on page 394
. If there is no
other fault, go to
“Final Tasks” on page 147
.
pin 2 of internal-options connector: received signal with 2.4V DC offset
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 ...