Sharp 64LHP5000, Service Manual

Page: 4 / 342

4
64LHP5000
PROJECTOR UNIT
Leakage Current Hot Check
Plug the AC line cord directly into a 120V AC 60Hz outlet ( do
not use an isolation transformer for this check). Turn the AC
power switch on.
Using a “Leakage Current Tester (Simpson Model 229
equivalent )”, measure for current from all exposed metal
parts of the cabinet ( input/output terminals, screwheads,
metal overlays, control shaft, etc. ), particularly any exposed
metal part having a return path to the chassis, to a known
earth ground (water pipe, conduit, etc.). Any current mea-
sured must not exceed 0.5mA.
Device
under
test
Leakage
current
tester
Reading should
not be above
0.5 mA
Also test with
plug reversed
(Using AC adapter
plug as required)
Test all
exposed metal
surfaces
X-radiation
TUBE: The primary source of X-radiation in this set is the
picture tube.
For continued X-radiation protection, the replacement tube
must be the same type as the original, SHARP approved
type.
The picture tube (the CRT assy R, G, B ) use in this set
holds complete guarantee against X-ray radiation when the
X-ray is sealed (See page 5). Accordingly, when the current
in flowing to the picture tube (CRT assy R, G, B) be sure to
perform it by putting the tube into X-ray sealed applied state.
Avoid absolutely to flow the current to the picture tube (CRT
assy R, G, B) itself. Moreover, when the voltage of the high
voltage circuit becomes abnormally a little higher, the pic-
ture tube radiates X-rays. Accordingly, when servicing the
high voltage circuit be sure to replace as an assembly with
the DEFLECTION SERVICE assy in the manner in which
has been adjusted to perform normal operation.
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in SHARP set have
special safety related characteristics. These are often not
evident from visual inspection nor the protection afforded by
them necessarily can be obtained by using replacement
components rated for higher voltage, wattage, etc. Replace-
ment parts which have these special safety characteristics
are identified in this Service Manual.
Electrical components having such features are identified by
marking with a
å
on the schematics and on the parts list in
this Service Manual.
The use of a substitute replacement component which does
not have the same safety characteristics as the SHARP rec-
ommended replacement one, shown in the parts list in this
Service Manual, may create shock, fire, X-radiation, or other
hazards.
Product Safety is continuously under review and new in-
structions are issued from time to time. For the latest infor-
mation, always consult the current SHARP Service Manual.
A subscription to, or additional copies of SHARP Service
Manual may be obtained at a nominal charge from SHARP.
ANY MEASUREMENTS NOT WITHIN THE LIMITS OUTLINED
ABOVE ARE INDICATIVE OF A POTENTIAL SHOCK HAZARD
AND MUST BE CORRECTED BEFORE RETURNING THE SET
TO THE CUSTOMER.
High Voltage
This set is provided with a X-ray protection for clearly indi-
cating that voltage has increased in excess of a predeter-
mined value. Comply with all notes described in this Service
Manual regarding this hold down circuit when servicing, so
that this X-ray protection may correctly by operated.
Serviceman Warning
In the status of the black picture ( video muting is being ap-
plied ) when no signal is input, high voltage of this set during
operation is less than 30.5kV. In case any component hav-
ing some relation to the high voltage is replaced, confirm
that the high voltage is lower than 30.5kV in the status of the
black picture when no signal is input.
To measure H.V. use a high impedance H.V. meter.
Connect ( – ) to earth and ( + ) to the FBT anode cable con-
nector.
(Refer to page 50)
Earth ground
AC Leakage Test
2-wire cord