Tektronix 7B92A Maintenance Manual page 49

remove the excess solder). Then straighten the tabs on
the socket and remove it from the hole in the 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.
END-LEAD PIN
connectors used to
interconnecting pins are clamped to the ends of the
associated leads. To replace damaged end-lead pin
connectors, remove the old connector from the end of
the lead and clamp the replacement connector to the
lead.
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 connector. To provide correct orientation of this
multi-pi n connector when it is replaced, an arrow (or dot)
is stamped on the circuit board and a matching arrow is
molded into the plastic housing of the multi-pin
connector. Be sure that these arrows are aligned when
the multi-pin connector is replaced. If the individual end-
lead pin connectors are removed from the plastic holder,
note the color of the individual wires for replacement.
Switches. Pushbutton and cam-type switches are
used in the 7B92A. Contact alignment and spacing is
critical to the operation of these switches. Therefore,
defective switches should be replaced as a unit or
repaired only by personnel experienced with switches of
this type. Your local Tektronix, Inc. Field Office can
provide additional repair information and instructions.
CAM SWITCH. The cam switch (TIME/DIV OR
DLY TIME and DLY'd Time/Division) consists of two
rotating cams and the associated contacts mounted on
the Interface and Readout boards. The cam switch can
be disassembled for cleaning, repair, or replacement;
however, it is recommended that the cam assembly be
removed from the instrument as a unit.
Remove the cam switch as follows: 1. Set the
TIME/DIV OR DLY TIME and DLY'D Time/Division
switches to 0.2 s and press the knob in.
2. Press and release the VARIABLE knob.
3. Loosen the set screws and remove the
VARIABLE and DLY'D Time/Division knobs.
REV A, JUN 1978
CONNECTORS. The
connect the wires
4. Loosen the set screw in the clear plastic flange
(behind sub-panel) and remove the TIME/DIV OR DLY
TIME flange.
5. Remove the pin connector from the micro-
switch (in front of the cam) to the front of the Interface
board.
pin
6. Remove the Sweep Logic board.
to the
7. Remove the 11 mounting screws holding the
cam switch assembly to the Interface board.
remove the mounting screws from the Readout board.
8. Carefully lift the cam-switch assembly and
Readout board from the interconnecting pins at the rear
of the Readout board.
9. To replace the cam-switch assembly, reverse
the above procedure. Be sure to replace the TIME/DIV
OR DLY TIME flange and the DLY'D Time/Division knob
in the same position from which they were removed.
TRIGGERING SWITCHES. Remove the Main and
Delayed Triggering switches as follows:
1. Perform steps 1 through 4 of the cam-switch
replacement procedure.
2. Loosen the set screws and remove all front
panel knobs except the DELAY TIME MULT dial.
3. Unsnap the front panel from the top and bottom
of the sub-panel.
4. Remove the spring from the 7B92A release
latch.
5. Remove the 4 screws holding the sub-panel to
the chassis and pull the sub-panel forward.
6. Remove all necessary multi-pin and coaxial
connectors.
7. Remove the mounting screws from the desired
switch(es).
8. The MAIN TRIGGERING switches must be
removed as an assembly (all three switches) and then
disassembled further.
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Maintenance-7B92A
Do not