156
Servicing Procedures
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
14.
If the main-board assembly was replaced or if the repair failed, re-
assemble the radio as described in
“Disassembly and Reassembly” on
. Conclude with the tasks of
Task 10 —
Check the Receive
and Receive-Audio
Functions
If the radio does not receive, this can be caused by:
■
the synthesizer not being in lock
■
no carrier detected
■
a faulty speaker or volume control
■
no modulation.
If the cause is already known, go directly to the relevant fault-finding
section.
1.
Use CCTM command
101 x y 0
to set the receive frequency to the
bottom of the band.
2.
Use CCTM command
72
to read the lock status.
3.
If the synthesizer is in lock, go to
. If the synthesizer is not in
lock, repair the radio as described in
4.
Repeat
to
with the receive frequency set to the top of
the band
5.
Feed a signal without modulation on the receive channel at –47dBm.
Check for maximum RSSI using:
■
the
indicator on the radio display (graphical display)
■
the green status LED
■
CCTM command
63
should return the fed signal strength
±1dBm.
6.
Repeat the check in
with –117dBm. The RSSI indicator
should show as empty or close to empty (graphical display).
7.
If the carrier is detected correctly, go to
. If the carrier is not
detected correctly, try to re-calibrate the radio.
8.
If the re-calibration repairs the fault, go to
If it does not, repair the radio as described in
9.
Check whether the speaker is the source of the fault, as described in
(graphical display) or
(1-, 2- or 3-digit display).
10.
If the radio receives audio now, the original speaker was faulty.
Reassemble the radio and go to
. If the
radio still fails to receive, reconnect the original speaker and go to
11.
Use CCTM command
804
to read the status of the volume
potentiometer.
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...
