Cisco 3800 Series - Manual (Page 110)

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Installing and Upgrading Internal Components in Cisco 3800 Series Routers
OL-5975-04
Removing the Cover from a Cisco 3825 Router
Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) can damage equipment and impair electrical circuitry. ESD can occur
when printed circuit cards are improperly handled and can result in complete or intermittent failures.
Always follow ESD prevention procedures when removing and replacing cards. Ensure that the router
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 router frame to safely channel
unwanted ESD voltages to ground. To guard against ESD damage and shocks, the wrist strap and cord
must be used properly. If no wrist strap is available, ground yourself by touching the metal part of the
router.
Caution For safety, periodically check the resistance value of the ESD-preventive wrist strap, which should be
between 1 and 10 megohms (Mohm).
Removing the Cover from a Cisco 3825 Router
You must remove the cover from a Cisco 3825 router to access the power supply and motherboard. The
router must be removed from the rack for this procedure. You will need number 1 and number 2 Phillips
screwdrivers.
If your router uses AC or DC power, observe the following warning:
Warning Do not touch the power supply when the power cord is connected. For systems with a power switch,
line voltages are present within the power supply even when the power switch is off and the power
cord is connected. For systems without a power switch, line voltages are present within the power
supply when the power cord is connected. Statement 4
If your router uses DC power, observe the following warning:
Warning Before performing any of the following procedures, ensure that power is removed from the DC circuit.
Statement 1003
Caution Before removing the cover, make sure that the CompactFlash memory card ejector button is flush with
the front panel. If the button projects from the panel, removing the cover can damage it.
Caution To prevent damage to the router, do not attempt to pry off the plastic bezel.
Step 1 Power down the router and disconnect the power cord from the front of the router.
Warning Before opening the unit, disconnect the telephone-network cables to avoid contact with
telephone-network voltages. Statement 1041
Step 2 Disconnect all network interface cables from the rear panel of the router.