Tait TM8000 Series, Руководство по обслуживанию

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TM8100 Mobile Radio Service Manual Servicing of Main Board 165
May 2004 © Tait Electronics Limited
8 Servicing of Main Board
Scope of Section
This section covers servicing of the main board following the initial
investigation described in
Subsection 5.2 (on page 109) . There are three
aspects:
■
fault diagnosis and repair of main board
■
replacement of faulty component
■
replacement of faulty main-board assembly
These aspects are described in Subsection 8.1 to Subsection 8.3
respectively. The initial investigation will have determined that the main
board is faulty.
Subsection 8.1 below gives the subsequent repair
procedure. Repair of the main board, however, is a level-2 repair. Level-
1 service centres should instead replace the complete main-board
assembly as described in
Subsection 8.3 (on page 169) . For level-2
service centres, Subsection 8.2 (on page 166) describes how to find the
correct replacement for a faulty component on the board.
8.1 Fault Diagnosis and Repair
Identify Suspect
Circuit Module
With the information gained from the initial investigation, identify
which module of the circuitry on the main board is faulty:
■
power-supply circuitry
■
interface circuitry
■
frequency synthesizer
■
frequency control loop
■
receiver
■
transmitter
■
CODEC and audio circuitry
Depending on which module is suspect, refer to Subsection 9.1 to
Subsection 9.7 respectively for the further fault diagnosis and repair of
the circuit.
Recalibration and
Reprogramming
During the above fault-diagnosis procedure, if the calibration is found to
be faulty at any time, recalibrate the radio before continuing. (Certain
restrictions might apply.) Similarly, if there is a problem with the radio
firmware, reprogram the radio before continuing. (Use a default
programming file if necessary.)