Tektronix 2445, Инструкция по эксплуатации

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Maintenance— 2445 Service
C A U T I O N
To p reven t g etting m oisture inside the instrum ent dur­
ing extern al cleaning, use only enough liquid to dam p­
en the cloth o r applicator.
CLEANING. Loose dust on the outside of the instrument
can be removed with a soft cloth or small soft-bristle brush.
The brush is particularly useful for dislodging dirt on and
around the controls and connectors. Dirt that remains can
be removed with a soft cloth dampened in a mild detergent-
and-water solution. Do not use abrasive cleaners.
Two plastic light filters, one blue and one clear, are pro­
vided with the oscilloscope. Clean the light filters and the crt
face with a soft lint-free cloth dampened with either isopro­
pyl alcohol or a mild detergent-and-water solution.
Interior
To gain access to internal portions of the instrument for
inspection and cleaning, refer to the “Removal and Replace­
ment Instructions” in the “Corrective Maintenance” part of
this section.
INSPECTION.
Inspect the internal portions of the 2445
for damage and wear, using Table 6-3 as a guide. Deficien­
cies found should be repaired immediately. The corrective
procedure for most visible defects is obvious; however, par­
ticular care must be taken if heat-damaged components are
found. Overheating usually indicates other trouble in the in­
strument; therefore, it is important that the cause of over­
heating be corrected to prevent recurrence of the damage.
If any electrical component is replaced, conduct a Perfor­
mance Check for the affected circuit and for other closely
related circuits (see Section 4). If repair or replacement work
is done on any of the power supplies, conduct a complete
Performance Check and, if so indicated, an instrument read­
justment (see Sections 4 and 5).
Table 6-3
Internal Inspection Check List
Item Inspect For Repair Action
Circuit Boards Loose, broken, or corroded solder
connections. Burned circuit boards.
Burned, broken, or cracked circuit-
run plating.
Clean solder corrosion with an eraser and flush with isopropyl
alcohol. Resolder defective connections. Determine cause of
burned items and repair. Repair defective circuit runs.
Resistors Burned, cracked, broken, blistered. Replace defective resistors. Check for cause of burned
component and repair as necessary.
Solder Connections Cold solder or rosin joints. Resolder joint and clean with isopropyl alcohol.
Capacitors Damaged or leaking cases. Corrod­
ed solder on leads or terminals.
Replace defective capacitors. Clean solder connections and
flush with isopropyl alcohol.
Semiconductors Loosely inserted in sockets.
1 la M
i m a
u i d i u i i c u p n o .
Firmly seat loose semiconductors. Remove devices having
distorted pins. Carefully straighten pins (as recjusred to fit the
socket), using long-nose pliers, and reinsert firmly. Ensure
that straightening action does not crack pins, causing them to
break off.
Wiring and Cables Loose plugs or connectors. Burned,
broken, or frayed wiring.
Firmly seat connectors. Repair or replace defective wires or
cables.
Chassis Dents, deformations, and damaged
hardware.
Straighten, repair, or replace defective hardware.
6-3