14V Power Supply; Frequency Synthesizer Fault Finding - Tait TM9100 Service Manual

First check the output
Task 3 —

14V Power Supply

with a 9V DC supply from a 9V regulator in the PSU module.
1.
2.
3.
4.
5.
6.
7.
8.
174

Frequency Synthesizer Fault Finding

VCL SUPPLY
Remove the main-board assembly from the chassis.
Place the radio in CCTM.
Measure the SMPS output
R530 (see Figure 9.2).
C531: 14.2 V ± 0.3 DC
If the SMPS output is correct, go to
Check the 9 V supply at Q500 and R533 (see
Q500 and R533: 9.0 V ± 0.3 DC
If the voltage is correct, go to
IC601 is suspect; go to Task 3
page 158.
Remove the can and check the SMPS circuit based on Q500,
FCL TOP
Q502 and L502 (see Figure
Remove the can and check IC504 and IC505 for shorts
SYN BOT
(see Figure 9.4); replace any suspect IC.
If a fault is found, repair the circuit, confirm the removal of the fault,
and go to "Final Tasks" on page
could be found, replace the main-board assembly and go to
Tasks" on page 147.
from the SMPS, which is itself provided
at the via between C531 and
VCL SUPPLY
Task 4. If it is not, go to
Figure
Step 7. If it is not, the 9V regulator
of "Power Supply Fault Finding" on
9.3).
147. If the repair failed or no fault
TM9100 Service Manual
© Tait Electronics Limited August 2005
Step 5.
9.3).
"Final