Maintenance-213
Service
NOTE
New crt's
are
supplied with the trace rotation
coil already installed.
If
the trace rotation
coil is faulty, contact the nearest Tektronix
Field Office or representative for assistance.
Reassembly.
To
reassemble
the
crt
assembly,
proceed
as
follows:
1.
Insert
the
crt
into
the
shield
with
the
trace
rotation
coil
leads
on
the
opposite
side
from
the
shield
seam.
Insert
the
crt
support
ring
from
the
crt
socket
end
of
the
shield,
and
carefully
push
it
down
inside
the
shield
with
a small
blunt
instrument
until
it
is
about
1
/8
inch
beyond
the
soldered
lead
on
the
shield.
2.
Reinsert
the
shield
lead
terminal
connector
into
the
plastic
holder.
CRT REPLACEMENT.
Replace
the
crt
assembly
in
the
reverse
order
of
Removal.
Insure
that
the
seam
on
the
crt
shield
is
facing
toward
the
top
of
the
instrument.
POWER SUPPLY BOARD
REMOVAL.
To
remove
the
Power
Supply
Board,
perform
the
Removal
steps
of
all pre-
ceding
components,
except
the
crt,
then
proceed
as
follows:
1.
Disconnect
the
terminal
connector
holders
that
are
connected
to
the
Power
Supply
circuit
board
from
the
Secon-
dary
Power
Supply
and
the
PWR
(BTRY)
LED.
NOTE
Take care
in
removing this board,
as
there is
another terminal connector holder on the
instrument side
of
the
bottom
of
the board
which
is
disconnected after the board
is
removed.
2.
Gently
I
ift
the
board
up
and
just free
of
the
Amp
I ifier
Board,
then
tilt
the
top
away
from
the
instrument
and
dis-
connect
the
terminal
connector
holder
that
is
on
the
cable
from
the
crt
base
socket.
Disassembly.
Further
disassembly
involves
removing
the
shields
for
troubleshooting,
repair,
or
replacement
of
parts.
Proceed
as
follows
(see
Figure
4-5):
4-6
WARNING
I
If
this board
is
to
be
reinstalled in the instrument
for troubleshooting, removal
of
the shields ex-
poses a shock hazard on the board. Also,
if
the
terminal connector holder from the Secondary
Power Supply Board (P420)
is
not
connected to
the Power Board and the instrument power
plug
is
connected to and then disconnected from
the power line, the two
large
capacitors (C417
and C418) under the shield on the parts side
of
the board do
not
discharge which could create
a possible shock hazard.
1. Being
careful
not
to
lose
the
small
spacers
under
the
laminate
shield
(on
soldered
side
of
board),
remove
the
three
screws
from
the
laminate
shield
and
remove
the
shields
on
both
sides
of
the
board.
2.
The
metal
I
ic
shield
can
be
further
disassembled
by
re-
moving
the
three
screws
holding
the
two
plastic
posts
and
one
metal
post
(note
that
the
metal
post
is
installed
on
the
board
adjacent
to
the
thick
film
resistor).
The
mylar
in-
sulator
attached
to
the
metal
shield
is
held
in
place
with
a
piece
of
double-stick
tape.
Reassembly.
Reassemble
the
shields in
the
reverse
order
of
Disassembly.
If
difficulty
is
encountered
in
keeping
the
ring
spacers
in place
under
the
laminate
shield
during
re-
assembly,
two
suggested
methods
for
reassembly
are
as
follows:
1.
For
the
first
method,
set
the
metal
shield
with
the
mylar
insulator
in
place
on
the
board
and
place
these
on
a
flat
surface
with
the
board
on
top.
Place a ring
spacer
on
the
board
hole
nearest
the
power
line
cord,
insert
a
screw
through
the
corresponding
hole
in
the
laminate
shield,
set
the
shield
in
place,
and
just
tighten
the
screw
until
the
threads
catch
hold.
Gently
lift
the
laminate
shield
and
place
a ring
spacer
over
the
board
hole
near
the
ASTI G
adjustment
hole.
Then
insert
a
screw
and
again
just
tighten
it
until
the
threads
catch
hold.
Slide
the
last
ring
spacer
in
place
over
the
hole
near
the
battery
terminal
pins,
insert
a
screw,
and
then
tighten
al
I
the
screws.
2.
For
the
second
method,
install
the
screws
in
the
laminate
shield
and
set
it
on
a
flat
surface
with
the
writing
side
of
the
shield
down.
Install
the
ring
spacers
and
set
the
board
in
place
on
top
of
the
spacers.
Remove
the
posts
from
the
metal
shield
and
install
them
on
the
laminate
shield
screws.
Then
install
the
metal
shield
with
its
mylar
insulator,
and
install
and
tighten
its
attaching
screws.
@
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