
TP9100 Service Manual
Frequency Synthesizer Fault Finding
169
© Tait Electronics Limited
May 2005
Task 6 —
3V Power Supply
If the SMPS output and the 5V and 4.3 V supplies are correct, the remaining
power supply to check is the 3V DC supply.
1.
Measure the supply
+3
V
0
AN
at pins 7 and 15 of
IC503
(see
2.
If the voltage is correct, go to
“Phase-Locked Loop” on page 170
If it is not, go to
.
3.
Check the supply at
L506
(see
). The measurement point
is the via shown in the figure.
4.
If the voltage is correct, go to
. If it is not, the 3 V regulator
IC604
is suspect (see
).
5.
Measure the voltage
DIG
3
V AN EN
at pin 3 of
IC604
(see
).
6.
If it is correct, go to
. If it is not correct, go to
7.
Check the components in the path from
L506
to
IC503
. Also check
IC503; if necessary, replace IC503 (see
8.
If a fault is found, repair the circuit, confirm the removal of the fault,
and go to
. If the repair failed or no fault
could be found, replace the main board, and go to
pins 7 and 15 of IC503: 2.9
±
0.3V DC
L506: 2.9
±
0.3V DC
L506: 2.9
±
0.3V DC
Figure 9.4
Location of the 3V regulator IC604 (bottom side)
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 ...