
TP9100 Service Manual
CODEC and Audio Fault Finding
277
© Tait Electronics Limited
May 2005
Task 6 —
Check
SUI VOL DC
Input Signal
If the output of the voice-band CODEC is correct, but the signal level does
not vary as the volume control is varied, check the
SUI VOL DC
signal.
1.
Check the operation of the volume pot
RV1
(see
) as
“Volume Control Faulty” on page 142
.
2.
Check the voltage on
TP
908
(see
). As the volume varies,
the voltage should vary as follows:
3.
If the volume varies as expected, go to
. If it does not, go to
4.
Check and repair any soldering faults around
R900
(see
Q910
, and
R953
(see
5.
Confirm the removal of the fault and go to
. If the repair failed, replace the main board and go to
.
6.
Remove the
CDC TOP
can.
7.
Check the voltage at the junction of
C245
(non grounded end,
see
). As the volume varies, the voltage should vary as
follows.
If the voltage varies as expected, CODEC 1 (
IC204
,
see
) is suspect.
8.
Replace the main board and go to
.
TP908: 0.4 to 1.1V as volume varies
C245: 0.4 to 1.1V as volume varies
Summary of Contents for TP9100
Page 1: ...TP9100 portables Service Manual MPA 00005 01 Issue 1 00 May 2005 ...
Page 4: ...4 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 10: ...10 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 74: ...74 Circuit Descriptions TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 78: ...78 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 100: ...100 General Information TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 126: ...126 Disassembly and Reassembly TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 148: ...148 Interface Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 158: ...158 Power Supply Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 250: ...250 Transmitter Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 268: ...268 Receiver Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 294: ...294 Spare Parts TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 298: ...298 Antenna Identification Chart TP9100 Service Manual Tait Electronics Limited May 2005 ...