190
Frequency Synthesizer Fault Finding
TM9100 Service Manual
© Tait Electronics Limited
August 2005
Task 15 —
Check
DIG
SYN
FAST
Line
If the loop filter is suspect but the reference and feedback voltages are
correct, check the
DIG
SYN
FAST
line, which is input to the inverter.
1.
Enter the CCTM command
389 1
to set the synthesizer mode to fast.
2.
Measure the voltage at the collector of Q505 (see
Figure 9.4
).
The result should be:
3.
Enter the CCTM command
389 0
to set the mode to slow.
4.
Measure the voltage at the collector of Q505 (see
Figure 9.4
).
The result should be:
5.
If the voltages measured in
Step 2
and
Step 4
are correct, go to
Task 16
. If they are not, go to
Step 6
.
6.
Remove R105 (see
Figure 9.6
).
7.
Enter the CCTM command
389 1
to set the mode to fast.
8.
Measure the voltage at the via between R105 and the digital board
(see
Figure 9.6
). The result should be:
9.
Enter the CCTM command
389 0
to set the mode to slow.
10.
Measure the voltage at the via between R105 and the digital board
(see
Figure 9.6
). The result should be:
11.
If the voltages measured in
Step 8
and
Step 10
are correct, go to
Step 12
. If they are not, the digital board is faulty; replace the main-
board assembly and go to
“Final Tasks” on page 147
.
12.
Check and resolder R105 in position (see
Figure 9.6
), and check for
continuity between the collector of Q505 (see
Figure 9.4
) and the
digital board via R105.
13.
If a fault is found, repair the circuit, and confirm that the voltages are
now correct. If they are, go to
“Final Tasks” on page 147
. If they are
not, or if no fault could be found, replace the main-board assembly
and go to
“Final Tasks” on page 147
.
Q505 collector: 14.2
±
0.3 V DC (after entry of CCTM 389 1)
Q505 collector: 0 V DC (after entry of CCTM 389 0)
via at R105: 0 V DC (after entry of CCTM 389 1)
via at R105: 3.3
±
0.3 V DC (after entry of CCTM 389 0)
Summary of Contents for TM9100
Page 1: ...TM9100 mobiles Service Manual MMA 00017 01 Issue 1 August 2005 ...
Page 4: ...4 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 10: ...10 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 22: ...22 Introduction TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 62: ...62 Description TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 96: ...96 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 138: ...138 Disassembly and Reassembly TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 152: ...152 Servicing Procedures TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 168: ...168 Interface Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 244: ...244 Receiver Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 396: ...396 CODEC and Audio Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 420: ...420 Fault Finding of Control Head TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 426: ...426 Spare Parts TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 430: ...430 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 444: ...444 TMAA04 05 Ignition Sense Kit TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 448: ...448 TMAA10 01 Desktop Microphone TM9100 Service Manual Tait Electronics Limited August 2005 ...