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LEAKAGE CURRENT COLD CHECK
1. Unplug the AC cord and connect a jumper between the two
plug prongs.
Turn on the set.
Measure the resistance value with an ohmmeter
between
the jumpered AC plug and
each
exposed metallic
part such
as screwheads, inpullerminals, control shafts,
etc.
.
When the exposed metallic part has. a
return path to the
chassis.
the
reading
should be between 490~2 and
9M!1.
3.
When Ihe exposed melal does not have a return path to
the chassis. the reading must be infinite.
.
LEAKAGE CURRENt HOT CHECK (See Fig. 1)
1. Plug the AC cord directly into the AC outlet. Do not use an
isolation transformer during
this
check.
2. Connect a L5k!2, 10 watts resistor, in parallel with a
O. 15~F capacitor between each exposed metallic part and
an ground. Use a good ground, for example, a water pipe.
3. Use a Iligh impedance AC voltage meter (VTVM) to
measurelhe potential across the resistor.
4. Move the resistor connection to each exposed metallic part
.
.
and measure the. voltage present.
'.
5. Check .that
any potential does not exceed 0.75 vol! RMS.
.
..
A leakage current tester (Simposon Model 229 or equiv-
alent) may be used in the above hot check, in which case
any currenl measured must not exceed 1/2 milliamp. In
.
case any measurement is out of Ihe iimits specified. there
is a possibility of a shock hazard arid the set should
be repaired and rechecked before it is returned to the
customer.
~ ~
r-'--"-'-'
;
Hot-Check
Circuit
AC VOLTMETER
(i.-:J
I
I
1
O.15~F
.
t
TO
COL.D
j
INSTRUMENT'S
WATER PIPE
l
EXPOSED
l_.~
(EARTH GROUNO)
METAL PIIRTS
1.5110. lOW
.
-.-
Fig. 1
Fig. 1
.-~.
~ ~ ~
X-RADIATION
WARNING:
The potential source
of X-Radiation in the color
video projector is the High voltage section and
the projection lubes.
NOTE: It is important to use an accurate, periodically,
calibrated
high voltage meter.
1. Set to the bright
mode
by using menu selector button on
the projector.
Minimize
Brightness
by using
control level adjustment
button.
2. Measure the High Voltage.
The high voltage meter should
indiCate 32kV:!:O.5kV. If the upper meter indication is oul of
tolerance, immediate service
and correction is
required
to
prevent the possibility
of premature
component
railure.
(Refer
to high
voltage adjustment in the manual.)
3. To prevent an
X-Radiation possibility,
it is essential
to use
the specified projection
tube only.
4. To prevent exposure to X-Radiation,
the projection
tube
shield must be kept in place with power
applied to the
set.
WARNING:
When using a projection tube test jig lOt service,
ensure that jig is capable of handling 32.5kV
without causing X-Radiation.
HORIZONTAL OSC. DISABLE CIRCUIT TEST
This test must be made as a final check before the set is
returned to the customer.
.
1. With the chassis case removed. supply a nominal 120V AC
to the set, turn on the set.
2. Set the customer controls to normal operating positions.
3. Press the TEST
button
once on the remole control
and
display
Internal crosshatch of NTSC sync.
4. Short the C6046 with a jumper wire.
5. Short theA6068 wilh a jumper wire.
Confirm vanish the high voltage. and reaster stop.
and
120V:t10V
on the voltmeter.
6. If this
does not occur,
the Horizontal Ose. Disable Circuit is
nol operating. Follow the Horizontal Ose. Disable
Circuit
Repair
Procedures before the set is returned 10 the
customer.
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