Operating instructions
Maintenance-71380
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
pro-
vide
additional
repair
information
.
The
following
special
maintenance
information
is
provided
for switch
replace-
ment
.
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
in-
spection, cleaning,
repair,
or
replacement
;
however,
it is
recommended
that
the switch
be
removed
and
replaced as
a
unit
.
Refer
to Figure
4-9
for
special
instructions
on
cam
switch
removal
.
Repair
of a
cam
switch
should
be
undertaken
only
by
experienced
maintenance
personnel
.
Switch alignment
and
contact
spacing
must
be
carefully
maintained
for
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
.
PUSH-BUTTON
SWITCHES
.
Removal
and
replacement
in-
structions for
push-button
switches
are
shown
in
Figure
4-10
.
Fig
.
4-8
.
Coaxial
end-lead
connector
assembly
.
Semiconductors
To avoid
component
damage,
power
must
be
turned
off
before
removing
or
replacing
semiconductors
.
Semiconductors
should
not
be replaced
unless
actually
de-
fective
.
If
semiconductors
are
removed
during
routine
main-
tenance,
return
them
to
their
original
sockets
.
Unnecessary
replacement
of
semiconductors
may
affect
the
adjustment
of
this
instrument
.
When
semiconductors
are
replaced,
check the
operation
of that
part
of
the
instrument
which
may
be
affected
.