1 Precautions
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 circuit
board.
2. Disconnect the AC power and DC power jack 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 theFigure 1-1. Leakage Current Test Circuit
following safety checks:
1. Inspect each lead dress to make certain that the leads are4. With the unit completely reassembled, plug the AC line
not pinched or that hardware is not lodged between thecord directly into a 120V AC outlet. With the unit?s AC
chassis and other metal parts in the monitor.switch first in the ON position and then OFF, measure
2. Inspect all protective devices such as nonmetallic controlthe current between a known earth ground (metal water
knobs, insulating materials, cabinet backs, adjustmentpipe, conduit, etc.) and all exposed metal parts,
and compartment covers or shields, isolation resistor-including: metal cabinets, screwheads and control shafts.
capacitor networks, mechanical insulators, etc.The current measured should not exceed 0.5 milliamp.
3. Leakage Current Hot Check (Figure 1-1): Reverse the power-plug prongs in the AC outlet and
repeat the test.
WARNING : Do not use an isolation
transformer during this test.
Use a leakage current tester or a metering system that1-1-4 Product Safety Notices
complies with American National Standards InstituteSome electrical and mechanical parts have special safety-
(ANSI C101.1, Leakage Current for Appliances), andrelated characteristics which are often not evident from visual
Underwriters Laboratories (UL Publication UL1410,inspection. The protection they give may not be obtained by
59.7).replacing them with components rated for higher voltage,
wattage, etc. Parts that have special safety characteristics are
identified by on schematics and parts lists. A substitute
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.
1-1 |
ACEC
