TM8100/TM8200 Service Manual
CODEC and Audio Fault Finding
381
© Tait Electronics Limited
June 2006
13
CODEC and Audio Fault Finding
Fault Conditions
This section covers the diagnosis of faults in the CODEC and audio
circuitry. There are five conditions that indicate a possible fault in the
circuitry:
■
no speaker audio or speaker audio is distorted
■
no speaker audio at auxiliary connector
■
receiver does not operate
■
no transmit modulation or modulation is distorted
■
no transmit modulation despite modulation at auxiliary connector
In the first case regarding the speaker audio, the green
STATUS
LED will be
operating correctly and all unmute criteria will be satisfied. In the second
case the receiver will be operating normally. In the third case the assumption
is that the receiver and power-supply circuitry were checked and no faults
were found. In the fourth case regarding the transmit modulation, the radio
will be transmitting the correct amount of RF power. In the fifth case the
transmitter will be operating normally.
Fault-Diagnosis
Procedures
The procedures for diagnosing the above faults are given below in the
following sections. In each case, however, first carry out the tasks of
. Also note that the conditions concerning the
auxiliary connector can both occur at the same time. In this case carry out
both
“No Speaker Audio at Auxiliary Connector” on page 391
and
Modulation Using Auxiliary Connector” on page 402
CCTM Commands
The CCTM commands required in this section are listed in
.
Full details of the commands are given in
.
Table 13.1
CCTM commands required for the diagnosis of faults in the CODEC and audio circuitry
Command
Description
21
Unmute received audio
32
Set radio in receive mode
33
Set radio in transmit mode
110
x
Set level
x
(in range 0 to 255) of audio volume
323
x y
Generate audio tone
AUD
TAP
IN
at tap point
x
of tap type
y
324
x y
Output audio signal at tap point
x
of tap type
y
to
AUD
TAP
OUT
400
x
Select channel with channel number
x
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
