
180
Frequency Synthesizer Fault Finding
TP9100 Service Manual
© Tait Electronics Limited
May 2005
Task 14 —
Check Feedback
Voltage
If the loop filter is suspect but the reference voltage is correct, check the
feedback voltage.
1.
Measure the feedback voltage at pin 6 of
IC505
(see
).
The result should be:
2.
If the voltage is not correct, the loop filter is faulty; go to
.
If the voltage is correct, resolder
R542
in position (see
and go to
.
3.
Check
IC504
,
IC505
,
Q511
(see
C548
(see
), and associated components.
4.
If a fault is found, repair the circuit, repeat the measurement of the
feedback voltage in
, and resolder
R542
in position
(see
).
5.
If the feedback voltage is now correct, go to
. If it is not, or if no fault could be found, replace the main
board, and go to
IC505 pin 6:
2.5
±
0.1V DC
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 ...