TM8100 Mobile Radio
Service Manual
Diagnosis of Faults on Main Board
181
May 2004 © Tait Electronics Limited
Task 2 —
Check Input Lines
For an input line suspected or reported to be faulty, proceed as follows:
1.
For a suspect
CH
ON
OFF
line, go to Step 4. For all other input lines
go to Step 2.
2.
For the suspect line, apply a 3.3 V DC test signal to a connector
mated to the radio connector in question.
3.
Check the internal signal for the line under test. If 3.3 V DC is
present, go to Step 7. If it is not, go to Step 8.
4.
For the
CH
ON
OFF
line, apply a short to ground on pin 5 of a
connector mated to the control-head connector. Check that there
is 3.9 V DC present on the
ITF
ON
OFF
line, and that
PSU
ON
OFF
is
approximately equal to the radio’s primary supply voltage,
nominally 13.8 V DC.
5.
Remove the short on the connector. Check that, with
CH
ON
OFF
open-circuit, both
ITF
ON
OFF
and
ITF
PSU
ON
OFF
are close to 0.0 V.
6.
If the voltages given in Steps 4 and 5 are observed, go to Step 7.
If they are not, go to Step 8.
Figure 9.6
Components of the interface circuitry on the top-side of the main board near the
CDC
TOP
and
IF TOP
cans
CDC TOP CAN
IF TOP CAN
Summary of Contents for TM8000 Series
Page 32: ...32 Introduction TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Page 78: ...78 Circuit Descriptions TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Page 106: ...106 General Information TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
Page 124: ...124 Servicing Procedure TM8100 Mobile Radio Service Manual May 2004 Tait Electronics Limited ...
