1 Precautions
Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as
electrical shock.
1-1 Safety Precautions
1-1-1 Warnings
1. For continued safety, do not attempt to modify the
(READING SHOULD
circuit board.NOT BE ABOVE 0.5mA)
2. Disconnect the AC power and DC Power Jack
before servicing.LEAKAGE
DEVICECURRENT
UNDERTESTER
TEST
1-1-2 Servicing the LCD Monitor
TEST ALL
EXPOSED METAL
1. PBA and panel components are very sensitive toSURFACES
static electricity. Always wear anti-static gloves
2-WIRE CORD
when handling PBA or panel. Use an anti-static
wrist strap and/or work bench. Keep parts in
protective bags until ready for use.ALSO TEST WITH
PLUG REVERSED
2. Do not use or apply excessive force when handling(USING AC ADAPTERPLUG AS REQUIRED)
EARTH
panel. Damage to liquid crystal display may resultGROUND
from improper handling.
Figure 1-1. Leakage Current Test Circuit
1-1-3 Fire and Shock Hazard
4. With the unit completely reassembled, plug the AC
Before returning the monitor to the user, perform the
line cord directly into a 120V AC outlet. With the
following safety checks:
unitOs AC switch first in the ON position and then
1. Inspect each lead dress to make certain that the
OFF, measure the current between a known earth
leads are not pinched or that hardware is notground (metal water pipe, conduit, etc.) and all
lodged between the chassis and other metal parts inexposed metal parts, including: metal cabinets,
the monitor.screwheads and control shafts. The current
2. Inspect all protective devices such as nonmetallicmeasured should not exceed 0.5 milliamp. Reverse
control knobs, insulating materials, cabinet backs,the power-plug prongs in the AC outlet and repeat
adjustment and compartment covers or shields,the test.
isolation resistor-capacitor networks, mechanical
insulators, etc.
1-1-4 Product Safety Notices
3. Leakage Current Hot Check (Figure 1-1):
WARNING: Do not use an isolation transformer during Some electrical and mechanical parts have special
this test.safety-related characteristics which are often not
evident from visual inspection. The protection they give
Use a leakage current tester or a metering system
may not be obtained by replacing them with
that complies with American National Standards
components rated for higher voltage, wattage, etc. Parts
Institute (ANSI C101.1, Leakage Current for
that have special safety characteristics are identified by
Appliances), and Underwriters Laboratories (UL
!on schematics and parts lists. A substitute
Publication UL1410, 59.7).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.
192MP1-1 |
ACEC
