Tektronix 442, Инструкция по эксплуатации

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Maintenance—442 Service
Interconnecting Cable and Pin Connector
Replacement
Interconnecting cable assemblies are factory
assembled with machine installed pin connectors (for
individual leads or multi-lead assemblies mounted in
plastic holders). Two types of multi-pin connectors are
used in the 442, with different size holders.
If the larger multi-pin holder assemblies are damaged,
the entire assembly should be replaced as a unit (refer to
the Replaceable Mechanical Parts section for part
numbers and ordering information.
The smaller multi-pin connector assemblies permit
replacement of the individual wire/connector units in the
holders, but the preferred method is to replace the entire
assembly if a contact is damaged.
It is possibleforthe pin connectors to become dislodg­
ed from the smaller plastic holders. If this happens, refer to
Figure 5-6 and the following steps for re-installation
details:
NOTE
To provide correct indexing of the multi-pin connec­
tors when they are re-connected to the matching
pins on a circuit board, a triangular index mark is
stamped on the circuit board. A matching index
mark, the brand name, or the numeral 1 will be
molded into the plastic housing of the connector to
indicate pin 1. Be sure to match the index marks
before re-installing the connectors. If the individual
end-lead pin connectors are removed from the
plastic holder, note the color of the insulation on the
individual wires for reference when the connectors
are re-installed in the holders.
1. Bend the slotted portion of the holder awayfromthe
wire leads as shown.
( 2 0 4 2 -3 6 1 2 3 7 4 -2 2 A
Figure 5-6. Pin connector re-installation in multi-pin holders.
2. Re-install the connector into the correct hole in the
plug-in portion of the holder. Note color code on wire
insulation to determine correct hole in the holder.
3. Bend the slotted portion of the holder back to its
original position so connectors are captivated in the
holder.
Readjustment After Repair
After any electrical component has been replaced, the
adjustments for that particular circuit should be checked,
as well as the adjustment of other closely related circuits.
Since the power supply affects all circuits, adjustment of
the entire instrument should be checked if work has been
done in the power supply or if the transformer has been
replaced.
Shaft/Knob Assembly Removal
The INTENSITY, Horizontal POSITION, LEVEL, and
FOCUS shaft/knob assemblies are of a one-piece con­
struction and can be removed or replaced as follows:
1. Grip the knob with one hand and the shaft with
the other hand.
2. Pull ontheknobwhilepushingontheshafttofree
the recessed portion of the shaft from the panel
retainer bushing (see Figure 5-7).
Some shaft/knobs may require considerable force to
remove, and the bushing and shaft may separate
abruptly. To avoid damage to the potentiometer and
the circuit board, or personal injury, grip both pieces
firmly during the shaft/knob removal. It may be
helpful to grip the shaft with the tip of a pair of long-
nose pliers and use a gentle rocking motion to
separate the shaft/knob from the panel bushing and
from the potentiometer shaft. Potentiometers with
long mounting terminals can bend easily or damage
the connections to the board, and therefore should
be held firmly while the shaft/knob assembly is
being disconnected from the potentiometer shaft.
REV A MAY 1980
5-15