TM8100/TM8200 Service Manual
CODEC and Audio Fault Finding
383
© Tait Electronics Limited
June 2006
Task 3 —
2.5V Power Supply
If the 9V and 3V supplies are correct, the remaining power supply to check
is the 2.5V DC supply (
+2
V
5
CDC
).
1.
Measure the voltage
+2
V
5
CDC
at pin 5 of
IC604
(see
).
2.
If the voltage is correct, go to
. If it is not, go to
3.
The 2.5V regulator
IC604
is suspect (see
). Check the
“Power Supply Fault Finding” on
4.
Proceed to the section relevant to the fault exhibited:
■
(distorted or no speaker audio)
■
“No Speaker Audio at Auxiliary Connector”
(no speaker audio at
auxiliary connector)
■
(receiver does not operate)
■
(distorted or no transmit modulation)
■
“Faulty Modulation Using Auxiliary Connector”
(modulation at
auxiliary connector only)
Further details are given in the introduction to the section.
Figure 13.1
Power-supply circuitry for the CODEC and audio circuitry under the
CDC
BOT
can
LO2 BOT CAN
CAN FOR
DIGITAL
BOARD
pin 5 of IC604: 2.5
±
0.3V DC
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...