Samsung VPL500 Service Manual Download

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11. High voltage is maintained within specified

limits by close-tolerance, safety-related compo-
nents and adjustments. If the high voltage
exceeds the specified limits, check each of the
special components.

12. Design Alteration Warning :

Never alter or add to the mechanical or elec-
trical design of this unit. Example : Do not
add auxiliary audio or video connectors. Such
alterations might create a safety hazard. Also,
any design changes or additions will void the
manufacturer’s warranty.

13. Hot Chassis Warning :

Some TV receiver chassis are electrically
connected directly to one conductor of the AC
power cord. If an isolation transformer is not
used, these units may be safely serviced only
if the AC power plug is inserted so that the
chassis is connected to the ground side of the
AC source.

To confirm that the AC power plug is inserted
correctly, do the following : Using an AC
voltmeter, measure the voltage between the
chassis and a known earth ground. If the read-
ing is greater than 1.0V, remove the AC power
plug, reverse its polarity and reinsert. Re-mea-
sure the voltage between the chassis and
ground.

14. Some TV chassis are designed to operate with

85 volts AC between chassis and ground,
regardless of the AC plug polarity. These units
can be safely serviced only if an isolation trans-
former inserted between the receiver and the
power source.

15. Never defeat any of the B+ voltage interlocks.

Do not apply AC power to the unit (or any of
its assemblies) unless all solid-state heat sinks
are correctly installed.

16. Always connect a test instrument’s ground

lead to the instrument chassis ground before
connecting the positive lead; always remove
the instrument’s ground lead last.

17. Observe the original lead dress, especially near

the following areas : Antenna wiring, sharp
edges, and especially the AC and high voltage
power supplies. Always inspect for pinched,
out-of-place, or frayed wiring. Do not change
the spacing between components and the

printed circuit board. Check the AC power
cord for damage. Make sure that leads and
components do not touch thermally hot parts.

18. Picture Tube Implosion Warning :

The picture tube in this receiver employs
“integral implosion” protection. To ensure
continued implosion protection, make sure
that the replacement picture tube is the same
as the original.

19. Do not remove, install or handle the picture

tube without first putting on shatterproof gog-
gles equipped with side shields. Never handle
the picture tube by its neck. Some “in-line”
picture tubes are equipped with a permanently
attached deflection yoke; do not try to remove
such “permanently attached” yokes from the
picture tube.

20. Product Safety Notice :

Some electrical and mechanical parts have
special safety-related characteristics which
might not be obvious from visual inspection.
These safety features and the protection they
give might be lost if the replacement compo-
nent differs from the original--even if the
replacement is rated for higher voltage,
wattage, etc.

Components that are critical for safety are
indicated in the circuit diagram by shading,
( or ).
Use replacement components that have the
same ratings, especially for flame resistance
and dielectric strength specifications.

A replacement part that does not have the

same safety characteristics as the original
might create shock, fire or other hazards.

Samsung Electronics

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Precautions