Tektronix 7B10 Instruction Manual page 43

Maintenance--7B1
0
7.
Remove
Interface circuit
board
through
rear of
instrument.
To
install
the Interface
circuit
board:
1.
Guide
TIME/DIV
switch shaft
through
hole
in
front
panel.
2. Install
6
screws
that
secure perimeter
of
board
to
instrument frame.
3. Install
gray
plastic rear
panel with
4
securing screws.
4.
Replace
TIME/DIV
knob on
shaft.
Align
knob
index
with
2
ms
position; then, tighten 2 set
screws on
knob.
5.
Replace
VARIABLE
knob and
tighten set screw.
6.
Replace
all
cables as noted during
removal
procedure.
7.
Replace Trigger
circuit board.
SWITCHES
Two
types
of
switches
are
used
in this
instrument.
Contact
alignment
and
spacing
are
critical to
the
operation
of
the push-button
and
cam
switches.
Therefore, defective
switches should
either
be replaced
as
a unit or
repaired only by
personnel experienced with
these types
of
switches.
Your
local
Tektronix Field Office
or
representative
can provide
additional repair
information.
The
following special
maintenance
information
is
provided
for
switch replacement.
Fig.
4-7. Coaxial end-lead connector assembly.
A1
-Interface Circuit
Board
To
remove
circuit
board:
1.
Remove
Trigger
and Readout
circuit
boards using
procedures given
previously.
2.
Set
TIME/DIV knob
to
2
ms
position
and
VARIABLE
TIME/DIV
knob
to
expose
the
set
screw.
3.
With hex-key wrench, loosen
set
screws
in
both knobs.
Remove
knobs from
shafts.
4.
Note
color of
multi-pin connectors
(see
Fig.
4-4
for
identification)
and P
numbers
to
which each
connect.
Disconnect
all
multi-pin
connectors from
board.
5.
Remove 4
screws
that
secure gray
plastic rear
panel
to
instrument frame.
6.
Remove
6 screws
that
secure perimeter
of
board
to
instrument frame.
Cam
Switches
Cam
switches
consist
of
a rotating
cam
that
mates
with
contacts
on
the adjacent
circuit
board.
These
contacts are
activated
by lobes
on
the
cam
as the switch
is
rotated.
A
cam
switch can be
disassembled
for
inspection, cleaning,
repair, or
replacement; however,
it
is
recommended
that
the switch
be
removed and
replaced as
a unit.
Refer
to
Figure
4-8
for
special
instructions
on
cam
switch
removal.
I
CAUTION
^
'>
(,
^
^
^ ^
Cam
switch
repair
should be undertaken
only
by
experienced maintenance
personnel.
Switch alignment
and
contact
spacing
must
be
carefully
maintained
(or
proper
operation.
A cam
switch
repair
kit is
available (Tektronix
part
040-0541-00) which
contains special
alignment
tools for
use
in
repairing or
replacing the switch
contacts.
For information
or
assistance
on maintenance
of
cam
switches, contact
your local Tektronix Field
Office or representative.
4-10