230
Frequency Synthesizer Fault Finding
TM8100/TM8200 Service Manual
© Tait Electronics Limited
November 2007
Task 30 —
Repair VCO
If either or both the maximum and minimum frequencies are incorrect, the
VCO circuitry is faulty.
1.
Remove the
VCO
BOT
can.
2.
Check the VCO. The circuitry is based on
Q5000
(see
Figure 9.15
).
3.
If a fault is found, repair it and go to
Step 4
. If no fault is found, go
to
Step 7
.
4.
Repeat
Step 1
and
Step 2
of
Task 28
to measure the maximum VCO
frequency.
5.
Repeat
Step 4
and
Step 5
of
Task 28
to measure the minimum VCO
frequency.
6.
If the frequencies are now correct, resolder
R542
in position
(see
Figure 9.14
), and go to
“Final Tasks” on page 163
. If they are
still not correct, go to
Step 7
.
7.
Resolder
R542
in position (see
Figure 9.14
). Replace the board and
go to
“Final Tasks” on page 163
.
Summary of Contents for TM8100 mobiles
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 05 Issue 5 November 2007...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 12: ...12 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 20: ...20 Introduction TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 64: ...64 Description TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 106: ...106 TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 134: ...134 General Information TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 168: ...168 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
Page 464: ...464 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited November 2007...
