Tait TM8100 mobiles, Service Manual

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TM8100/TM8200 Service Manual Fault Finding of Control Head with 1-, 2- or 3-Digit Display 447
© Tait Electronics Limited November 2007
15 Fault Finding of Control Head with
1-, 2- or 3-Digit Display
Overview
This section describes the fault finding of the control head with 1-, 2- or 3-
digit display for the following faults:
■
display faulty but not LEDs
■
some LEDs faulty
■
all LEDs faulty
■
display and all LEDs faulty
■
some but not all keys faulty
■
all keys faulty
■
speaker faulty
■
volume control faulty
The faults can be detected by visual inspection (refer to “Check the
User Interface” on page 159 ).
General
The following applies for all fault finding procedures:
Important
Do not disconnect or connect the control head while
power is supplied to the radio.
■
If the radio does not switch on when power is supplied, the radio may
be programmed to go into the status it was in when powered down.
Connect a known good control head, power up the radio, and change
the relevant setting in the programming application. Remember to
program the original setting before returning the radio to the customer.
■
For disassembly and re-assembly instructions, refer to “Disassembling
and Reassembling the Control Head” on page 147 .
■
If the repair fails or no fault could be found, replace the control-head
board.
■
After completing the repair, carry out the tasks in “Initial Tasks” on
page 155 .