196
Frequency Synthesizer Fault Finding
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
Task 10 —
SYN
LOCK
Line
If all the critical inputs to the PLL are correct, check the
SYN
LOCK
line
output.
1.
Enter the CCTM command
72
to determine the lock status in receive
mode. Note the status.
2.
Check the
SYN
LOCK
line by measuring the voltage at pin 14 of
IC503
(see
). The voltage should depend on the lock status as
follows:
3.
If the voltage measured in
is correct, go to
. If it is not, go to
4.
Check for continuity between pin 14 of
IC503
and the digital board
via
R568
(see
) and
L102
(see
5.
If there is a fault, go to
. If there is no fault, the digital board is
faulty; replace the board and go to
.
6.
Repair the fault. Confirm the removal of the fault and go to
. If the repair failed or no fault could be found,
replace the board and go to
lock status=
xyz
(
x
=RF PLL;
y
=FCL;
z
=LO2) (0=not in lock; 1=in lock)
lock status 111 or 110: 3.0
±
0.3 V DC at pin 14 of IC503
lock status 011 or 010: 0 V DC at pin 14 of IC503
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...
