Tait TM8000 Series, Service Manual

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TM8100 Mobile Radio Service Manual General Information 91
May 2004 © Tait Electronics Limited
4.4 SMT Repair Techniques
Standard Procedures
Service centres carrying out level-2 repairs are expected to be familiar
with the standard techniques for the replacement of SMT components.
However, certain components on the main board require non-standard
techniques and these are discussed below. Another issue of concern is
the procedure for removing and installing cans. A discussion of the issue
concludes this subsection.
Non-standard
Procedures
Do not use the standard SMT repair techniques when replacing the
capacitors C548 and C565 and the inductors L601 and L602. The
standard techniques tend to produce excessive heat, which will damage
these components. Do not use a hot-air tool or heat gun. Instead use
solder paste and a standard soldering iron with a number-6 iron tip. The
capacitors are part of the frequency-synthesizer circuitry under the
SYN TOP
can. The inductors are part of the SMPS of the power-supply
circuitry on the bottom-side of the board. Figure 4.2 shows the
locations of the components.
Can Removal
and Installation
Cans are best removed and installed using a can-removal tool. If this tool
is available, technicians should refer to the documentation supplied with
the tool for the correct procedures. If the tool is not available, a hot-air
tool may be used instead. However, technicians require training in the
best techniques to employ in the absence of a can-removal tool. Such
training is part of the accreditation process for service centres.
Spare Cans
It is good practice to discard any can that has been removed and replace
it with a spare can from Spares kit 5. If this is not done, special
precautions are needed when re-installing the original can. These
precautions are discussed as part of the training for accreditation.