TM8100/TM8200 Service Manual
CODEC and Audio Fault Finding
397
© Tait Electronics Limited
June 2006
Task 11 —
Check
QN
Test Point
If the level shifter is not faulty, check the signal at the
QN
test point. This will
ascertain whether the digital board, CODEC 1, or the receiver is at fault.
1.
Use the programming application to find the frequency selected for
channel 1.
2.
Apply a strong on-channel signal.
3.
Check that a sine wave is present at the
QN
test point
(there is access
through a hole in the
IF
TOP
can — see
4.
If there is a sine wave present, go to
. If there is not, go to
“Receiver Fault Finding” on page 239
5.
Either the digital board or CODEC 1 (
IC204
) is faulty; replace the
board and go to
.
Figure 13.8
Circuitry in the vicinity of the
CDC
TOP
can (UHF shown)
Junction of
C708 and C732
QN test point: sine wave
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...