Tektronix 7T11A, Instruction Manual

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Maintenance— 7T1 1A
Circuit Board Pin Replacement
It is important not to damage or disturb the ferrule when
removing the old stub of a broken pin. The ferrule is pressed
into
the circuit board and provides a base for soldering the
pin connector (see Figure 4-5). If the broken stub is tong
enough, grasp it with a pair of long-nose pliers, and apply
heat with a small soldering iron to the pin base or the ferrule
so a firm pull is required to pull it out. If the broken stub is
too short to grasp with pliers, use a small dowel (0.028
inches in diameter) clamped in a vise to push the pin out of
the ferrule after the solder has been heated. The old ferrule
can be cleaned by reheating the solder and placing a sharp
object such as a toothpick or small dowel into the hole. A
vacuum-type solder removing tool is also useful for remov­
ing excess solder. Use a pair or diagonal cutters to remove
the ferrule from the new pin, then insert the pin into the old
ferrule, and solder the pin to both sides of the ferrule. If it is
necessary to bend the new pin, grasp the base of the pin
with long-nose pliers and bend against the pressure of the
pliers
to avoid breaking the board around the ferrule.
Circuit Board Pin Socket Replacement
The pin sockets on the circuit boards are soldered to the
rear of the board. To replace one of these sockets, first
unsolder the pin (use a vacuum-type desoldering tool to re­
move excess solder). Then straighten the tabs on the
socket and remove it from the hole in the circuit board.
Place the new socket in the circuit board hole and press the
tabs down against the board. Solder the tabs of the socket
to the circuit board; be careful not to get solder into the
socket.
NOTE
The spring tension of the pin sockets ensures a good
connection between the circuit board and the pin. This
spring tension can be destroyed by using the pin
sockets as a connecting point for spring-loaded probe
tips, alligator clips, etc.
Figure 4-5. Exploded view of circuit-board pin and ferrule.
End-Lead Pin Connector Replacement
The pin connectors used to connect wires to the inter­
connecting pins are clamped to the ends of the associated
leads. To replace damaged end-lead pin connectors, re­
move the old pin connector from the end of the lead and
clamp the replacement connector to the lead.
Coaxial End-Lead Connector Replacement (RF and
Peltola Connectors)
Replacement of coaxial-type end-lead connectors re­
quires special tools and techniques. We recommend that the
cable be replaced as a unit. For cable part numbers, see the
Replaceable Mechanical Parts List in Section 9. An alterna­
tive solution is to refer the replacement of the defective con­
nector to your local Tektronix Field Office or representative.
Multiple End-Lead Connector Replacement
Some of the pin connectors are grouped together and
mounted in a plastic holder; the overall result is that these
connectors are removed and installed as a multi-pin connec­
tor (see Figure 4-3). To provide correct orientation of this
multi-pin connector when it is replaced, an arrow is etched
on the circuit board and a matching arrow is molded into the
plastic holder of the connector. These arrows must be
aligned as the multi-pin connector is replaced. If the individ­
ual end-pin connectors are removed from the plastic holder,
note the color of the individual wires for replacement.
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