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1 Precautions
Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential haz-
ards such as electrical shock and X-rays.
1-1 Safety Precautions
1-1-1 Warnings
1. For continued safety, do not attempt to
modify the circuit board.
2. Disconnect the AC power before servicing.
3. When the chassis is operating, semiconductor
heat sinks are potential shock hazards.
1-1-2
Servicing the High Voltage
System and Picture Tube
1. When servicing the high voltage system,
remove the static charge by connecting a 10k
ohm resistor in series with an insulated wire
(such as a test probe) between the chassis and
the anode lead. (Disconnect the AC line cord
from the AC outlet.)
2. Do not lift the picture tube by the neck.
3. Handle the picture tube only when wearing
shatterproof goggles and after completely
discharging the high voltage anode.
1-1-3 X-Rays and High Voltage Limits
1. Keep the high voltage below the specified
maximum level. Be sure all service personnel
are aware of the procedures and instructions
covering X-rays.
The only potential source of X-ray in current
solid state display monitors is the tube.
However, the picture tube does not emit
measurable X-ray radiation if the high
voltage is as specified in the fire and shock
hazard instruction. Only when high voltage is
excessive are X-rays capable of penetrating the
shell of the picture tube, including the lead in
glass material.
;
2.
It is essential that service technicians have an
accurate high voltage meter available at all
times. Check the calibration of this meter
periodically.
Samsung Electronics SyncMaster 17GLi
3. High voltage should always be kept at the
rated value, no higher. Operation at high
voltages may cause failure of the picture tube
or high voltage circuitry and, also under
certain conditions, may produce X-rays in
excess of acceptable levels.
4, When the high voltage regulator is operating
properly there is no possibility of an X-ray
problem. Test the brightness and use a meter
to monitor the high voltage each time a color
monitor comes in for service. Make sure the
high voltage does not exceed its specified
value and that it is regulating correctly.
5. The picture tube is especially designed to
prohibit X-ray emissions. To ensure continued
X-ray protection, replace the picture tube only
with one that is the same type as the original.
Carefully reinstall the picture tube shields and
mounting hardware; these also provide X-ray
protection.
6. When troubleshooting a monitor with
excessively high voltage, avoid being
unnecessarily close to the monitor. Do not
operate the monitor longer than is necessary
to locate the cause of excessive voltage.
1-1-4 Fire and Shock Hazard
Before returning the monitor to the user, perform
the following safety checks:
1. Inspect each lead dress to make certain that
the leads are not pinched or that hardware is
not lodged between the chassis and other
metal parts in the monitor.
2. Inspect all protective devices such as
nonmetallic control knobs, insulating
materials, cabinet backs, adjustment and
compartment cover or shields, isolation
resistor-capacitor networks, mechanical
insulators, etc.
1-1
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