TM8100/TM8200 Service Manual
Frequency Synthesizer Fault Finding
189
© Tait Electronics Limited
June 2006
Task 5 —
5V Power Supply
If the SMPS output and 6V DC supply are correct, check the
+5
V
DEC
supply next.
1.
Remove the
SYN
TOP
can.
2.
Measure the supply
+5
V
DEC
at pin 4 of
Q508
(see
3.
If the voltage is correct, go to
. If it is not, go to
radios) or
(VHF radios).
4.
With a UHF radio check for faults in the C-multiplier
Q508
(pins 3,
4, 5) and the 5V and transmit-receive switches based on
Q506
,
Q507
and
Q508
(pins 1, 2, 6) (see
). Replace any suspect
transistor. Conclude with
5.
With a VHF radio, check for faults in the C-multiplier and 5V switch
based on
Q508
and
Q5004
(see
). Remove the
SYN
TOP
can (A4 band only) and
VCO
BOT
can, and check the transmit-receive
switch based on
Q5002
and
Q5003
(see
). Replace any
suspect transistor. Conclude with
6.
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 board and go to
pin 4 of Q508: 5.3
±
0.3V DC
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...