Component Removal And Replacement - Tektronix 7B92A Maintenance Manual

The reason some component leads are
troublesome to remove is due to a bend
placed on each
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 soldered connection.
Use only enough heat to remove the component
lead without removing the solder from the board. If it is
desired to remove solder from a circuit-board hole for
easier installation of a new component, a solder-
removing wick should be used.
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, cut the leads so
they will just protrude through the board. Insert the leads
into the holes 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.
5. Clip any excess lead protruding through the
board (if not clipped in step 3).
6. Clean the area around the solder connection
with a flux-removing solvent. Be careful not to remove
information printed on the board.

Component Removal and Replacement

Disconnect the instrument from the
power source
components.
Semiconductors. Semiconductor devices used in this
instrument should not be replaced unless actually
defective. If removed from their sockets during routine
maintenance, return them to their original sockets.
Ferrite beads must be reinstalled on the proper leads.
REV A, JUN 1978
NOTE
lead during the
WARNING
before replacing
Unnecessary replacement may affect the calibration of
this instrument.
check the operation of the part of the instrument that
may be affected.
Replacement devices should be of the original type
or a direct replacement. Install in the same manner as
the original. Figure 4-2 shows the lead configurations of
the semiconductor devices used in this instrument.
When replacing, check the manufacturer's basing
diagram for correct basing.
Interconnecting
interconnection are used in this instrument to connect
the circuit boards with other boards and components.
When the interconnection is made with a coaxial cable, a
special end lead connector plugs into a socket on the
board. Other interconnections are made with a pin
soldered onto the board.
connectors are used for these interconnecting pins. If
the mating connector is mounted on a plug-on circuit
board, a special socket is soldered into the board. If the
mating connector is on the end of a lead, an end-lead pin
connector that mates with the interconnecting pin is
used. The following
replacement procedure for the various interconnecting
methods.
COAXIAL-TYPE
Replacement of the coaxial-type end-lead connectors
requires special tools and techniques. Only experienced
maintenance personnel should attempt replacement of
these connectors. It is recommended that the cable or
wiring harness be replaced as a unit. For cable or wiring
harness part numbers, see the Replaceable Mechanical
Parts list. An alternate solution is to refer the
replacement of the defective connector to your Tektronix
Field Office or representative.
CIRCUIT BOARD PINS AND PIN SOCKETS. A
circuit board pin replacement kit, including necessary
tools, instructions, and replacement pins, is available
from Tektronix, Inc. (Tektronix Part Number 040-0542-
00.)
The following
recommended for single-layer circuit
boards
replacement on multi-layer circuit boards
should be performed only by qualified
service personnel. Refer to your local
Tektronix Field Office or Service Center.
The pin sockets on the circuit boards are soldered
to the board. To replace one of these sockets, first
unsolder the pin socket (use vacuum-type desoldering
tool to
4-9
Maintenance-7B92A
When a semiconductor is replaced,
Pins. Two
Two types of mating
information
END-LEAD CONNECTORS.
CAUTION
procedures
only. Pin and
methods of
provides the
are
socket