244
Receiver Fault Finding
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
Task 3 —
Check Logic Signal
If there is no fault with the power supplies, check the logic signal
DIG RX EN
that is input from the digital board.
1.
Check the logic signal
DIG RX EN
at pin 8 of
IC403
(see
The signal is active high. The required status is active.
An alternative measurement point to the above is pin 24 of
IC400
under the
IF TOP
can (see
2.
If
DIG RX EN
is active, go to
.
3.
Check the signal continuity from the digital board to the receiver.
Repair any fault and go to
. If the digital board itself appears to
be faulty, replace the board and go to
.
4.
Recalibrate the receiver using the calibration application.
5.
Confirm the removal of the fault and go to
. If the repair failed, go to
.
Task 4 —
Check Lock Status
If the logic signal from the digital board is active, as required, check the lock
status of the radio.
1.
Enter the CCTM command
72
to determine the lock status.
The status should be normal:
2.
If the lock status is normal, go to
. If the LO1 is not in lock, go
“Frequency Synthesizer Fault Finding” on page 179
. If the FCL is
not in lock, go to
“Power Supply for FCL” on page 227
. If the LO2
is not in lock, go to
3.
Check the components around
IC403
,
Q402
and
Q403
(see
). Repair any fault.
4.
Recalibrate the receiver using the calibration application.
5.
Confirm the removal of the fault, and go to
. If the repair failed go to
pin 8 of IC403: about 3.0V (active)
lock status: 111 (LO1, FCL, LO2 all in lock)
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...