Important Safety Precautions - Sampo SME-23DL3 Series Service Manual

IMPORTANT SAFETY PRECAUTIONS

1. Before returning an instrument to the
customer, always make a safety check of the
entire instrument, including, but not limited to,
the following items.
a. Be sure that no built-in protective devices are
defective and/or have been defeated during
servicing. (1) Protective shields are provided on
this chassis to protect both the technician and
the customer. Correctly replace all missing
protective shields, including any removed for
servicing convenience. (2) When reinstalling the
chassis and/or other assembly in the cabinet,
be sure to put back in place all protective
devices, including,
nonmetallic control knobs, insulating fishpapers,
adjustment and compartment covers/shields,
and isolation resistor/capacitor networks. Do
not operate this instrument or permit it to be
operated without all protective devices
correctly installed and functioning.
b. Be sure that there are no cabinet openings
through which an adult or child might be able
to insert their fingers and contact a hazardous
voltage, Such opening include, but are not
limited to, (1) spacing between the picture
tube and the cabinet mask, (2) excessively
wide cabinet ventilation slots, and (3) an
improperly fitted and/or incorrectly secured
cabinet back cover.
c. Leakage Current Hot Check « « « « With the
instrument completely reassembled, plug the
AC line cord directly into a 120V AC outlet. (Do
not use an isolation transformer during this test.)
Use a leakage current tester or a metering
system that complies with American National
Standards Institutes (ANSI) C101.1 Leakage
Current for Appliances
Laboratories (UL) 478. With the instrument AC
switch first in the ON position and then in the
OFF position, measure from a known earth
ground (metal waterpipe, conduit, etc.) to all
exposed metal
(antennas, handle bracket, metal cabinet,
screwheads, metallic overlays, control shafts,
etc.), especially any exposed metal parts that
offer an electrical return path to the chassis.
Any current measured must not exceed 3.5
milliamp. Reverse the instrument power cord
plug in the outlet and repeat test. ANY
MEASUREMENTS NOT WITHIN THE LIMITS
SPECIFIED HEREIN INDICATE A POTENTIAL
but not limited
and Underwriters
parts of the instrument
SHOCK
ELIMINATED BEFORE RETURNING THE
INSTRUMENT TO THE CUSTOMER.
AC Leakage Test
DEVICE
UNDER
TEST
to,
2. Read and comply with all caution and
safety-related notes on or inside the Monitor
cabinet, on the Projection Monitor chassis, or
on the picture tube.
3. Design Alteration Warning « « « « Do not alter or
add to the mechanical or electrical design of
this unit. Design alterations and additions,
including,
modifications and the addition of the items such
as auxiliary
connections
characteristics of this Projection Monitor and
create a hazard to the user. Any design
alterations
manufacturer's warranty and will make you, the
service, responsible for personal injury or
property damage resulting therefrom.
4. Hot Chassis Warning « « « « a. Some Monitor
chassis are electrically connected directly to
one conductor of the AC power cord and may
be safely
transformer only if the AC power plug is
inserted so that the chassis is connected to the
ground side of the AC power source. To
confirm that the AC power plug is inserted
correctly,
between the chassis and a known earth ground.
If a voltage reading in excess of 1.0V is
obtained, remove and reinsert the AC power
plug in opposite polarity and again measure the
voltage potential between the chassis and a
- 1-1 -
HAZARD THAT
LEAKAGE
CURRENT
TESTER
+ -
TEST ALL
EXPOSED METAL
SURFACES
3. WIRE CORD
ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
but not limited
audio and/or
might alter
or additions will
serviced without
with an AC voltmeter measure
VER 1.0
MUST BE
(READING
SHOULD NOR
BE ABOVE
3.5mA)
EARTH
GROUND
to, circuit
video output
the safety
void the
an isolation