Bose 1600-VI Service Manual download pdf (Page 4)

SAFETY INFORMATION

ELECTROSTATIC DISCHARGE SENSITIVE (ESDS)

DEVICE HANDLING

This unit contains ESDS devices. We recommend the following precautions when repairing,

replacing or transporting ESDS devices:

• Perform work at an electrically grounded work station.

• Wear wrist straps that connect to the station or heel straps that connect to conductive floor

mats.

• Avoid touching the leads or contacts of ESDS devices or PC boards even if properly

grounded. Handle boards by the edges only.

• Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unpro-

tected devices into materials such as plastic, polystyrene foam, clear plastic bags, bubble wrap

or plastic trays.

1. Parts that have special safety characteristics are identified by the symbol on schemat-

ics or by special notes on the parts list. Use only replacement parts that have critical character-

istics recommended by the manufacturer.

2. Make leakage current or resistance measurements to determine that exposed parts are

acceptably insulated from the supply circuit before returning the unit to the customer. Use the

following checks to perform these measurements:

A. Leakage Current Hot Check-With the unit completely reassembled, plug the AC line cord

directly into a 120V AC outlet. (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)

1492 (71). With the unit AC switch first in the ON position and then in OFF position, measure

from a known earth ground (metal waterpipe, conduit, etc.) to all exposed metal parts of the

unit (antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts,

etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any

current measured must not exceed 0.5 milliamp. Reverse the unit power cord plug in the outlet

and repeat test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN

INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RE-

TURNING THE UNIT TO THE CUSTOMER.

B. Insulation Resistance Test Cold Check-(1) Unplug the power supply and connect a

jumper wire between the two prongs of the plug. (2) Turn on the power switch of the unit. (3)

Measure the resistance with an ohmmeter between the jumpered AC plug and each exposed

metallic cabinet part on the unit. When the exposed metallic part has a return path to the

chassis, the reading should be between 1 and 5.2 Megohms. When there is no return path to

the chassis, the reading must be "infinite". If it is not within the limits specified, there is the

possibility of a shock hazard, and the unit must be repaired and rechecked before it is returned

to the customer.

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Bose 1600-VI Service Manual Page 4