Safety Guidelines

Prerequisites

The following guidelines will help to ensure your safety and protect the equipment. This list is not inclusive of all potentially hazardous situations, so be alert.

•Always turn all power supplies off and disconnect power cords before removing the top front chassis panel. Dangerous current levels are present on the backplane when power is on.

•Do not work alone when potentially hazardous conditions exist.

•Carefully examine your work area for possible hazards such as moist ﬂoors, ungrounded power extension cables, and missing safety grounds.

•Before beginning any procedures requiring access to the chassis interior, locate the emergency power-off switch for the room in which you are working.

•Never assume that power has been disconnected from a circuit; always check.

In addition, use the guidelines that follow when working with any equipment that is connected to telephone wiring or other network cabling.

•Never install telephone wiring during a lightning storm.

Warning Do not work on the system or connect or disconnect cables during periods of lightning activity. (For translation of this safety warning, refer to the section “Lightning Activity Warning” on page 15.)

•Never install telephone jacks in wet locations unless the jack is speciﬁcally designed for wet locations.

•Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the network interface.

•Use caution when installing or modifying telephone lines.

Warning Before opening the chassis, disconnect the telephone-network cables to avoid contact with telephone-network voltages. (For translation of this safety warning, refer to the section “Chassis Warning—DisconnectingTelephone-Network Cables” on page 15.)

Caution Always handle an LED board by the edges only; avoid touching the board components, traces, or connector pins.

Preventing Electrostatic Discharge Damage

Electrostatic discharge (ESD) damage, which occurs when electronic boards or components are improperly handled, can result in complete or intermittent failures. The processor modules each comprise a printed circuit board that is ﬁxed in a metal carrier. Electromagnetic interference (EMI) shielding, connectors, and a handle are integral components of the carrier. The LED board, however, is not intended to be handled and has no frame or shielding. Handle the LED board by the edges only; never touch the board components, traces, or connector pins.

Following are guidelines for preventing ESD damage:

•Always use an ESD strap and ensure that it makes good skin contact.

6Cisco 7000 and Cisco 7507 LED Board Replacement Instructions