Section 6 Maintenance Instructions; Preventive Maintenance; Cleaning; Lubrication - Tektronix TR 502 Instruction Manual

Introduction
MAINTENANCE INSTRUCTIONS
Maintenance for the TR 502 consists of preventive
steps to reduce the possibility of instrumentfailure and the
corrective measures to take if trouble or a malfunction
should occur.
PREVENTIVE MAINTENANCE
Preventive maintenance consists of cleaning, visual
inspection, performance check, and if needed, a recalibra-
tion . The preventive maintenance schedule that is es-
tablished for the instrument should be based on the
environment in which the instrument is operated and the
amount of use. Under average conditions (laboratory
situation) a preventive maintenance check should be
performed every 1000 hours of instrument operation.
Cleaning
Clean the instrument often enough to prevent dust or
dirt from accumulating in or on it . Dirt acts as a thermal
insulating blanket to prevent efficient heat dissipation and
in a humid environment high resistance electrical leakage
paths are provided between conductors or components .
Do not allow water to get inside any enclosed
assembly or components such as the hybrid
assemblies, RF
attenuator assembly, poten-
tiometers, etc. Do not clean any plastic materials
with organic cleaning solvents such as benzene,
toluene, xylene, acetone or similar compounds
because they may damage the plastic .
Lubrication
No components in this insturment require lubrication .
Visual Inspection
CAUTION
Section 6-TR 502
After cleaning, carefully check the instrument for such
defects as defective connections, damaged parts, and
improperly seated transistors and integrated circuits . The
remedy for most visible defects is obvious; however, if
heat-damaged parts are discovered, try to determine the
cause of overheating before the damaged part is replaced,
otherwise the damage may be repeated .
Exterior. Clean the dust from the outside of the
instrument by wiping or brushing the surface with a soft
cloth or small brush. The brush will remove dust from
Transistor and Integrated Circuit Checks
around the front panel selector buttons. Hardened dirt
Periodic checks of the transistors and integrated
may be removed with a cloth dampened with a mild
circuits are not recommended . The best measure of
detergent solution . Abrasive cleaners should not be used .
performance is the actual operation of the component in
the circuit. Performance
of these components is
thoroughly checked during the performance check or
Interior. Normally the interior of the instrument will not
recalibration . Any substandard transistors or integrated
require cleaning unless it has been left out of the
circuits will usually be detected at that time . More details
mainframe plug-in compartment and uncovered for an
on checking semiconductor operation are given under
extended period of time . Clean the interior by loosening
troubleshooting .
accumulated dust with a dry soft brush, then remove the
loosened dirt with low pressure air to blow the dust clear .
(High velocity air can damage some components .)
Hardened dirt or grease may be removed with a cotton
Performance Checks and Recalibration Schedule
tipped applicator dampened with a solution of mild
The instrument performance should be checked after
detergent in water. Abrasive cleaners should not be used .
each 1000 hours of operation or every six months,
If the circuit board assemblies need cleaning, remove the
whichever occurs first, to ensure maximum performance .
circuit board and wash with mild detergent solution, then
A performance check will also assist in locating defects
rinse and dry.
that may not be apparent during regular operation .
Instructions for conducting a performance check are
provided in the Performance Check section of this
After cleaning, allow the interior to thoroughly dry
manual . Recalibration should only be done if the instru-
before applying power to the instrument .
ment does not meet performance specifications .