electrostatic discharge (esd) can damage equipment and impair electrical circuitry. it can occur if electronic printed circuit cards are improperly handled and can cause complete or intermittent failures. always follow esd prevention procedures when removing and replacing modules:

    . ensure that the router chassis is electrically connected to earth ground.

    . wear an esd-preventive wrist strap, ensuring that it makes good skin contact. connect the clip to an unpainted surface of the chassis frame to channel unwanted esd voltages safely to ground. to guard against esd damage and shocks, the wrist strap and cord must operate effectively.

    . if no wrist strap is available, ground yourself by touching a metal part of the chassis.

    for the safety of your equipment, periodically check the resistance value of the antistatic strap. it should be between 1 and 10 megohms (mohm).