Maintenance; Preventive Maintenance; Cleaning; Visual Inspection - Tektronix 7B92A Maintenance Manual

This section of the manual contains information for performing preventive maintenance, troubleshooting, and corrective
maintenance for this instrument.
Preventive maintenance consists of cleaning, visual inspection, lubrication, etc. Preventive maintenance performed on a
regular basis may prevent instrument breakdown and will improve the reliability of the instrument. The severity of the
environment to which this instrument is subjected determines the frequency of maintenance. A convenient time to perform
preventive maintenance is preceding adjustment of the instrument.

CLEANING

This instrument should be cleaned as often as operating
conditions require. Accumulation of dirt on components
acts as an insulating blanket and prevents efficient heat
dissipation that can cause overheating and component
breakdown.
CAUTION
Avoid the use of chemical cleaning
agents which might damage the plastics
used in this instrument.
avoid chemicals that contain benzene,
toluene, xylem, acetone, or similar
solvents.
Exterior
Loose dust accumulated on the front panel can be
removed with a soft cloth or small brush.
remains can be removed with a soft cloth dampened with
a mild detergent and water solution. Abrasive cleaners
should not be used.
Interior
Dust in the interior of the instrument should be removed
occasionally due to its electrical conductivity under high-
humidity conditions. The best way to clean the interior is
to blow off the accumulated dust with dry, low pressure
air. Remove any dirt that remains with a soft brush or a
cloth dampened with a mild detergent and water solution.
A cotton-tipped applicator is useful for cleaning in narrow
spaces.

MAINTENANCE

PREVENTIVE MAINTENANCE

In particular,
Dirt that
Switch Contacts
Switch contacts and pads are designed to operate dry for
the life of the switch. However, as the switches are not
sealed, dust attracted to the contact area may cause
switch contacts to become electrically noisy. Cleaning
may be accomplished by flushing the contact area with
isopropyl alcohol or kelite (1 part kelite to 20 parts water).
Do not use chemical cleaning agents that leave a film or
that might damage plastic parts.
swabs or similar applicators to apply cleaning agents, as
they tend to snag and leave strands of cotton on switch
contacts. Should it become necessary to remove a
switch for replacement or cleaning, refer to Component
Removal and Replacement in this section.

VISUAL INSPECTION

This instrument should be inspected occasionally for
such defects as broken connections, improperly seated
semiconductors, damaged circuit boards, and heat-
damaged parts.
The corrective procedure for most visible defects if
obvious; however, particular care must be taken if heat-
damaged components are found. Overheating usually
indicates other trouble in the instrument; therefore, it is
important that the cause of overheating be corrected to
prevent recurrence of the damage.

LUBRICATION

Generally, there are no components in this instrument
that requires a regular lubrication program during the life
of the instrument.
4-1
Section 4-7B92A
Do not use cotton