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.
Warning
• For continued safety, do not attempt to modify the circuit board.
• Disconnect the AC power and DC power jack before servicing.
1-1-1. Servicing the Product
1. When servicing the Product, 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.
1-1-2. Fire and Shock Hazard
• Before returning the product 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 product.
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:
Warning
• Do not use an isolation transformer during
this test.
• Use a leakage current tester or a metering
system that complies with American
National Standards Institute (ANSI C101.1,
Leakage Current for Appliances), and
Underwriters Laboratories (UL Publication
UL1410, 59.7).
4. With the unit completely reassembled, plug the AC line cord directly into a 120V 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.
Reverse the power-plug prongs in the AC outlet and repeat the test.
1-1
Precautions
DEVICE
UNDER
TEST
(READING SHOULD)
NOT BE ABOVE 0.5mA
LEAKAGE
CURRENT
TESTER
TEST ALL
EXPOSED METAL
SURFACES
2-WIRE CORD
ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
EARTH
GROUND
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