408
CODEC and Audio Fault Finding
TM8100/TM8200 Service Manual
© Tait Electronics Limited
November 2007
Task 7 —
Check
ITF
RX
BEEP
IN
Input Signal
If the output of the voice-band CODEC is not correct, check the
ITF RX BEEP
IN
signal.
1.
If not already done, remove the
CDC
BOT
can.
2.
Check the signal at the junction of
R218
and
IC204
(see
Figure 13.4
). The signal should be:
3.
If the signal is correct, go to
Step 4
. If it is not, either CODEC 1
(
IC204
) or the digital board is faulty; replace the board and go to
“Final Tasks” on page 163
.
4.
Check for continuity between the
TP
200
test point
and
IC204
via
R214
,
R215
(see
Figure 13.2
) and
R218
(see
Figure 13.4
).
Repair any fault; if necessary, replace R214, R215 or R218.
5.
Confirm the removal of the fault and go to
“Final Tasks” on
page 163
. If the repair failed or the fault could not be found, replace
the board and go to
“Final Tasks” on page 163
.
junction of R218 and IC204: sine wave about 1V
pp
with 1.2V DC offset
Summary of Contents for TM8100 mobiles
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 05 Issue 5 November 2007...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 12: ...12 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 20: ...20 Introduction TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 64: ...64 Description TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 106: ...106 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 134: ...134 General Information TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 168: ...168 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 464: ...464 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...