Precautions; Safety Precautions - Samsung 650FP Service Manual

1. Precautions

1-1. Safety Precautions

Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as
electrical shock.
1-1-1. Warnings
1. For continued safety, do not attempt to modify the circuit board.
2. Disconnect the AC power before servicing.
1-1-2. Servicing the LCD Monitor
1. When servicing the LCD Monitor, Disconnect the AC line cord from the AC outlet.
2. It is essential that service technicians have an accurate voltage meter available at all times. Check the calibration of
this meter periodically.
1-1-3. 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 covers or shields, isolation resistorcapacitor networks, mechanical insulators, etc.
3. Leakage Current Hot Check (Figure 1-1):
WARNING : Do not use an isolation transformer during this test.
DEVICE
UNDER
TEST
TEST ALL
EXPOSED METAL
SURFACES
2-WIRE CORD
*ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
4. With the unit completely reassembled, plug the AC line cord directly into AC outlet. With the unit's AC switch first in the
ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit, etc.) and
all exposed metal parts, including: metal cabinets, screwheads and control shafts.
The current measured should not exceed 0.5 milliamp.
1-1-4. Product Safety Notices
Some electrical and mechanical parts have special safetyrelated characteristics which are often not evident from visual
inspection. The protection they give may not be obtained by replacing them with components rated for higher voltage,
wattage, etc. Parts that have special safety characteristics are identified by
replacement that does not have the same safety characteristics as the recommended replacement part might create
shock, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever
appropriate.
(READING SHOULD)
NOT BE ABOVE 0.5mA
LEAKAGE
CURRENT
TESTER
EARTH
GROUND
Figure 1-1. Leakage Current Test Circuit
on schematics and parts lists. A substitute
1. Precautions
1-1