3-2 Maintenance
dislodged material out and away from the inside of the radio . Make sure that controls or tunable
components are not soaked with alcohol. Do not use high-pressure air to hasten the drying process
since this could ca use the liquid to collect in unwanted places. After completing of the cleaning
process, use a soft, absorbent, lintless cloth to dry the area. Do not br ush or apply any isopropyl
alcohol to the frame, front cover, or back cover.
3.3 Safe Handling of CMOS and LDMOS Devices
Complement ary metal-oxide sem iconductor (CMOS) devices are us ed in this family of radios, and ar e
susceptible to damage by electrostatic or high voltage charges. Damage can be latent, resulting in
failures occurring weeks or months later. Therefore, special precautions must be taken to prevent
device damage during disassembly, troubleshooting, and repair.
Handling precautions are mandatory for CMOS circuits and are especially important in low humidity
conditions. DO NOT atte mpt to disassemble the r adio without first r eferring to the following CAUTION
statement.
3.4 Repair Procedures and Techniques — General
Parts Replacement and Substitution
When damaged p a rt s are replaced , ide ntical p a rt s should be used. If the identical replacement p art is
not locally available, check the parts list for the proper Motorola part number and or der the part from
the nearest Motorola Communications parts center listed in the “Piece Parts” section of this manual
(See page 1-2).
NOTE: Always use a fresh supp ly of alco hol and a cle an container to prevent contamination
by dissolved material (from previous usage).
CAUTION: This radio contains st at ic-s ens iti ve d evice s. Do not open the rad io unless
you are properly grounded. Take the following precautions when working on this
unit:
lStore and transport all CMOS devices in conductive materia l so that all exposed
leads are shor ted to ge th er. Do not insert CMOS devices into conventional plastic
“snow” trays used for storage and transport ation of other semiconductor devices.
lGround the working surface of the ser vice ben ch to protect th e CMOS device. W e
recommend using the Motorola Static Protection Assembly (part number
0180386A82), which includes a wrist strap, two ground cords, a table mat, and a
floor mat.
lWear a conductive wrist strap in series with a 100k resistor to ground.
(Replacement wrist straps that connect to the bench top covering are Motorola
part number RSX-4015.)
lDo not wear nylon clothing while handling CMOS devices.
lDo not insert or remove CMOS devices with power applied. Check all power
supplies used for testin g CMOS devices to be certain that ther e ar e no voltage
transients present.
lWhen straightening CMOS pins, provide ground straps for the apparatus used.
lWhen soldering, use a grounded soldering iron.
lIf at all possible, handle CMOS devices by the package and not by the leads. Prior
to touching the unit, touch an electrical ground to remove any static charge that
you may have accumulated. The package and substrate may be electrically
common. If so, the reaction of a di scharge to the case would cause the same
damage as touching the leads.
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