Interface Fault Finding; Internal And Connector Signals; Types Of Signals - Tait TM9100 Service Manual

8

Interface Fault Finding

This section covers the diagnosis of faults involving signals output from or
Introduction
input to the radio's internal circuitry via the control-head, internal options,
power, or auxiliary connectors. For most inputs and outputs, filtering or
basic processing is applied between the internal circuitry and the connectors.
The signals at the internal circuitry and those at the connectors are
Internal and
Connector Signals
distinguished as internal signals and connector signals respectively. On the
circuit diagram for the internal circuitry, dashed lines enclose connector
signals. Internal signals are all named signals outside these enclosures. In
Figure
example,
Figure 8.1 Example illustrating the convention for internal and connector signals
ITF_IOP_GPO7
ITF_IOP_GPO6
ITF_IOP_GPO5
The connector and internal signals can be of three types:

Types of Signals

For diagnosing faults in these three cases, carry out
respectively. Where components need to be replaced to rectify faults, refer
to
figures show the three areas of the main board where the components of the
interface circuitry are situated.
TM9100 Service Manual
© Tait Electronics Limited August 2005
8.1, which shows part of the internal options connector as an
7 is a connector signal and
IOP GPIO
+3V3_CL +3V3
D705
3 R723
BAV70W
33K
2
+3V3_CL +3V3
D706
3 R724
BAV70W
33K
1
+3V3_CL +3V3
D706
3 R725
BAV70W
33K
2
output lines
input lines
bi-directional lines
Figure 8.3 to Figure 8.4
ITF IOP GPIO
TO
INTERNAL
OPTIONS
CONNECTOR
R731
IOP_GPIO7
1B2
1K0
6B4
R732
IOP_GPIO6
1B2
1K0
R733
IOP_GPIO5
1B2
1K0
Task
for the locations of the components. These
Interface Fault Finding
7 is an internal signal.
1, Task 2 or Task 3
163