Canon Canovision8 E50E - Page 28

The
following
precautions
should
be
observed
when
servicing.»
=
Seas
7
+.
Since
many
parts
in
the
unit
have
special
safety-related
characteristics;
always
use
genuine
CANON
replacement
parts.
°- =
ot
.
:
:
:
Especially
critcal
parts
in
the
power
circuit
block
should
not
be
replaced
with
other
°
makes,
7
s
:
Critical
parts
are
marked
with
/\
in
the
schematic
diagrams.
2,
The
primary
source
of
X-ray
radiation
in
this
viewfinder
is
the
picture
tube.
The
tube
used
in
the
viewfinder
“is
especially
constructed
to
limit
X-ray
radiation
emission.
For
continued
X-ray
radiation
protection,
the
replacenent
tube
mist
be
same
type
as
the
original,
CANON
approved
one.
3.
When
servicing,
observe
the
original
lead
dress.
If
2
short
circuit
is
found
all
parts
which
have
been
oberheated
or
damaged
by
the
short
circuit,
4,
After
servicing,
see
to
it
that
all
the
protective
devices
barriers,
insulation
papers
shields
are
properly
installed.
5,
After
servicing,
make
the
following
leakage
current
checks
to
prevent
the
customer
: from being exposed to. shock hazards,
Leakage Current Cold Check ©
1),
Unplug
the
AC
cord
and
connect’
@
jumper
between
the
two
prongs
on
the
plug.
2).
Measure
the
resistance
value,
with
an
ohmmeter,
between
the
jumpered
AC
plug
and
each
exposed!
metalic
cabinet
part
on
the.
equipment
such
as
screwheads;.
connectors,
control
shafts;
ete.
When
the
exposed
metalic
part
has
a
return
path
to
the
chassis}.
the
reading
should
be
between
1M2
and
5.2M2.
When
the
exposed
ot
have
a
return
path
to
the
chassis,
the
reading
must
be.™,
Leakage Current’ Hot Check 2
» replace
such as insulation
5-1
Y.
the-unit ; ‘and'a good earth ground
_
Check
all
exposed
metaliié’
parts
of
the
cover,
(Cable’
connect:
on,
Handle
bracket
metallic
cabinet.
Screwheads;
Metallic
overlays,
etc),
and
measure
the
voltage
Reverse
the
AC
plug
in
the
AC
outlet
and
repeat
each
of
the
above
measurements,
The
potential
at
any
point
should
not
exceed
0.75V
RMS,
«A
leakage
current
tester
(FLUKE
MODEL:
8000A
equivalent)
may
be
used
to
make
the
hot
checks,
|
°*
es
"5
eae
Leakage
current
must
not
exceed
0.5
milliamp,
--
.
e
In
case
a
measurement
is
out
side
of
the
limits
Specified,
there
is
a
possibility
of
a
shock
hazard,
and
corrective
action
must
be
taken
before
returning
the
instrument
to
the
customer.
Water pipe
{ann Ground)
AC
OUTLET
"Figure
1,
Leakage
Current
Hor
Check