Tektronix 5110, Инструкция по эксплуатации

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Maintenance-5110
Ordering Parts
When ordering replacement parts from Tektronix, Inc.,
it is imperative that all of the following information be
included in the order to ensure receiving the proper parts.
1. Instrument type (5110, 5A18N, 5B10N, etc.).
2. Instrument serial number.
3. A description of the part (if electrical, include the
circuit number).
4. Tektronix part number.
SOLDERING TECH NIQUES
WARNING |
High voltage and current levels are present in this
instrument. To avoid electrical shock, disconnect
the instrument from the power source before solder­
ing.
The reliability and accuracy of this instrument can be
maintained only if proper soldering techniques are
used
when repairing or replacing parts. General soldering
techniques, which apply to maintenance of any precision
electronic equipment, should be used when working on
this instrument. Use only 60/40 rosin-core, electronic-
grade solder. The choice of soldering iron is determined
by the repair to be made. When soldering on circuit
boards, use a 15-to 40-watt pencil-type soldering iron with
a 1/8-inch wide, wedge-shaped tip. Keep the tip properly
tinned for best heat transfer to the solder joint. A higher
wattage soldering iron may separate the wiring from the
base material. Avoid excessive heat; apply only enough
heat to remove the component or to make a good solder
joint. Also, apply only enough solder to make a firm solder
joint; do not apply too much solder.
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Some circuit boards in this instrument are multi­
layer boards with a conductive path(s) laminated
between the top and bottom board layers. AH
soldering on these boards should be done with
extreme care to prevent breaking the connections to
the center conductor(s); only experienced
maintenance personnel should attempt repair on
these boards.
For metal terminals (e.g., switch terminals, poten­
tiometers, etc.) a higher wattage-rating soldering iron may
be required. Match the soldering iron to the work being
done. For example, if the component is connected to the
chassis or other large heat-radiating surface, it will require
a 75-watt or larger soldering iron.
The following technique should be used to replace a
component on a circuit board. Most components can be
replaced without removing the boards from the instru­
ment.
1. Grip the component lead with long-nose pliers.
Touch the soldering iron to the lead at the solder
connection. Do not lay the iron directly on the board, as it
may damage the board.
2. When the solder begins to melt, pull the lead out
gently. If unable to pull the lead without using force, try
removing the other end of the component as it may be
more easily removed.
NOTE
The reason some component leads are troublesome
to remove is due to a bend placed on each lead
during the manufacturing process. The bent leads
hold components in place during a process that
solders many components at one time.
If a component lead is extremely difficult to remove, it
may be helpful to straighten the leads on the back side of
the board with a small screwdriver or pliers while heating
the solder connection.
Unsolder the component from the circuit board, using
heat on the component lead so that the solder will stay
behind the board. If it is desired to remove solder from a
circuit-board hole for easier installation of a new compo­
nent, use a vacuum-type desoldering tool or a solder­
removing wick.
3. Bend the leads of the new component to fit the holes
in the board. If the component is replaced while the board
is mounted in the instrument, cutthe leads so they will just
protrude through the board. Insert the leads into the holes
in the board so the component is firmly seated against the
board (or as positioned originally). If it does not seat
properly, heat the solder and gently press the component
into place.
4. Touch the iron to the connection and apply a small
amount of solder to make a firm solder joint. To protect
heat-sensitive components, hold
the lead between the
component body and the solder joint with a pair of long-
nose
pliers or other heat sink.
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