
TP9100 Service Manual
Frequency Synthesizer Fault Finding
193
© Tait Electronics Limited
May 2005
Task 24 —
Repair PLL feedback
If both the minimum and maximum transmit frequencies are correct, the
PLL feedback is suspect.
1.
Resolder
R542
in position (see
2.
Remove the
VCO BOT
can.
3.
Replace the components
C570
,
R578
(see
) and
IC503
(see
4.
Confirm that the fault in the radio has been removed. If it has, go to
. If it has not, replace the main board, and
.
Task 25 —
Repair Transmit
VCO
If either or both the minimum and maximum transmit frequencies are
incorrect, the transmit VCO circuitry is faulty.
1.
Remove the
VCO TOP
can.
2.
Check the transmit VCO. The circuitry is based on
Q510
(see
3.
If a fault is found, repair it and go to
. If no fault is found, go
to
4.
Repeat the frequency measurements in
and
.
5.
If the frequencies are now correct, resolder
R542
in position
(see
), and go to
. If they are
6.
Resolder
R542
in position (see
). Replace the main
board and go to
.
Summary of Contents for TP9100
Page 1: ...TP9100 portables Service Manual MPA 00005 01 Issue 1 00 May 2005 ...
Page 4: ...4 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 10: ...10 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 74: ...74 Circuit Descriptions TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 78: ...78 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 100: ...100 General Information TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 126: ...126 Disassembly and Reassembly TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 148: ...148 Interface Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 158: ...158 Power Supply Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 250: ...250 Transmitter Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 268: ...268 Receiver Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 294: ...294 Spare Parts TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 298: ...298 Antenna Identification Chart TP9100 Service Manual Tait Electronics Limited May 2005 ...