Check Input Lines - Tait TM9100 Service Manual

For an input line suspected or reported to be faulty, proceed as follows:
Task 2 —

Check Input Lines

1.
2.
3.
4.
5.
6.
7.
8.
For a bi-directional line suspected or reported to be faulty, proceed as
Task 3 —
Bi-directional Lines
described below. In the procedure the direction of the line will need to be
configured. For information on this topic consult the on-line help facility
on the programming application's "Programmable I/O" page.
1.
2.
TM9100 Service Manual
© Tait Electronics Limited August 2005
For a suspect line, go to
CH ON OFF
to Step 2.
For the suspect line, apply a 3.3V DC test signal to a connector mated
to the radio connector in question.
Check the internal signal for the line under test. If 3.3V DC is
present, go to Step 7. If it is not, go to
For the line, apply a short to ground on pin 5 of a connector
CH ON OFF
mated to the control-head connector. Check that there is 3.9V DC
present on the
ITF ON OFF
equal to the radio's primary supply voltage, nominally 13.8V DC.
Remove the short on the connector. Check that, with
open-circuit, both
ITF ON OFF
If the voltages given in Step 4
If they are not, go to Step
The fault lies with the radio's internal circuitry. If the power-supply
circuitry or the CODEC and audio circuitry is suspect, continue with
the fault diagnosis as in "Power Supply Fault Finding" on page 153
and "CODEC and Audio Fault Finding" on page
If the digital board is suspect, replace the main-board assembly and go
to "Final Tasks" on page
The fault lies in the filtering, basic processing, or connector for the
line under test. Re-solder components or replace faulty com-ponents
as necessary. Confirm the removal of the fault and go to
on page 147. If the fault could not be found, replace the main-board
assembly and go to "Final Tasks" on page
Configure the suspect line as an output, and then carry out the
procedure given in Task
Configure the suspect line as an input, and then carry out the
procedure given in Task
Step 4. For all other input lines go
Step 8.
line, and that
PSU ON OFF
and are close to 0.0V.
ITF PSU ON OFF
and Step 5 are observed, go to
8.
147.
147.
1.
2.
Interface Fault Finding
is approximately
CH ON OFF
Step 7.
371, respectively.
"Final Tasks"
167