Tektronix 2440, Руководство пользователя

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Maintenance— 2440 Service
NOTE
Physical size and shape of a component may affect
instalment performance, particularly at high frequen­
cies. Always use direct-replacement components,
unless it is known that a substitute will not degrade
instrument performance.
Special Parts
In addition to the standard electronic components,
many special parts are used in this scope. These com­
ponents are manufactured or selected by Tektronix, Inc. to
meet specific performance requirements, or are manufac­
tured
for Tektronix, Inc. in accordance with our
specifications. The various manufacturers can be identified
by referring to the “Cross Index— M FR Code Number to
Manufacturer" at the beginning of the “Replaceable Electri­
cal Parts’ list. Most of the mechanical parts used in this
instrument were manufactured by Tektronix, Inc. Order all
special parts directly from your local Tektronix Field Office
or representative.
Ordering Parts
When ordering replacement parts from Tektronix, Inc.,
be sure to include all of the following information:
1. Instrument type (include modification or option
numbers).
2. Instrument serial number.
3. A description of the part (if electrical, include its
full circuit component number).
4. Tektronix part number.
MAINTENANCE AIDS
The maintenance aids listed in Table 6-5 include items
required for performing most of the maintenance pro­
cedures in this instrument. Equivalent products may be
substituted for the examples given, provided their charac­
teristics are similar.
INTERCONNECTIONS
Interconnections in this instrument are made with pins
soldered onto the circuit boards. Several types of mating
connectors are used for the interconnecting pins. The fol­
lowing information provides the replacem ent procedures
for the various types of connectors.
End-Lead Pin Connectors
Pin connectors used to connect the wires to the inter­
connect pins are factory assembled. They consist of
machine-inserted pin connectors mounted in plastic hold­
ers. If the connectors are faulty, the entire wire assembly
should be replaced.
Multipin Connectors
When pin connectors are grouped together and
mounted in a plastic holder, they are removed, reinstalled,
or replaced as a unit. If any individual wire or connector in
the assembly is faulty, the entire cable assembly should be
replaced. To provide correct orientation of a multipin con­
nector, an index arrow is stam ped on the circuit board,
and either a matching arrow is molded into or the numeral
1 is marked on the plastic housing as a matching index.
Be sure these index marks are aligned with each other
when the multipin connector is reinstalled.
TRANSISTORS AND
INTEGRATED CIRCUITS
Transistors and integrated circuits should not be
replaced unless they are actually defective. If removed
from their sockets or unsoldered from the circuit board
during routine maintenance, return them to their original
board locations. Unnecessary replacem ent or transposing
o f semiconductor devices may affect the adjustm ent of the
instrument. When a semiconductor is replaced, check the
perform ance of any circuit that may be affected.
Any replacem ent component should be of the original
type or a direct replacem ent. Bend transistor leads to fit
their circuit board holes, and cut the leads to the same
length as the original component. See Figure 9-2 in the
“ Diagrams” section for lead-configuration illustrations.
)
C A U T I O N
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After replacing a power transistor, check that the
collector is not shorted to the chassis before apply­
ing power to the instrument.
6-12