Safety Precautions; Electrostatic Discharge-Esd Protection - Dell NOT22427 Owner's Manual

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5. Remove any media card and optical disk from your computer, if applicable.
6. Enter the service mode, if you are able to power on your computer.
Service Mode
Service Mode is used to cut-off power, without disconnecting battery cable from system board prior conducting repairs in
the computer.
CAUTION:
If you are unable to turn on the computer to put it into Service Mode, or the computer does not
support Service Mode, proceed to disconnect the battery cable. To disconnect the battery cable, follow the
steps in
Removing the
NOTE:
Ensure that your computer is shut down and the AC adapter is disconnected.
a. Hold <B> key on the keyboard and press the power button for 3 seconds or until the Dell logo appears on the screen.
b. Press any key to continue.
c. If the AC adapter is not disconnected, a message prompting you to remove the AC adapter appears on the screen.
Remove the AC adapter and then press any key to continue the Service Mode process. The Service Mode process
automatically skips the following step if the Owner Tag of the computer is not set up in advance by the user.
d. When the ready-to-proceed message appears on the screen, press any key to proceed. The computer emits three short
beeps and shuts down immediately.
e. Once the computer shuts down, it has successfully entered Service Mode.
NOTE:
If you are unable to power on your computer or unable to enter Service Mode, skip this process.

Safety precautions

The safety precautions chapter details the primary steps to be taken before performing any disassembly instructions.
Observe the following safety precautions before you perform any installation or break/fix procedures involving disassembly or
reassembly:
● Turn off the system and all attached peripherals.
● Disconnect the system and all attached peripherals from AC power.
● Disconnect all network cables, telephone, and telecommunications lines from the system.
● Use an ESD field service kit when working inside any to avoid electrostatic discharge (ESD) damage.
● After removing any system component, carefully place the removed component on an anti-static mat.
● Wear shoes with non-conductive rubber soles to reduce the chance of getting electrocuted.
Standby power
Dell products with standby power must be unplugged before you open the case. Systems that incorporate standby power are
essentially powered while turned off. The internal power enables the system to be remotely turned on (wake on LAN) and
suspended into a sleep mode and has other advanced power management features.
Unplugging, pressing, and holding the power button for 15 seconds should discharge residual power in the system board.
Bonding
Bonding is a method for connecting two or more grounding conductors to the same electrical potential. This is done through
the use of a field service electrostatic discharge (ESD) kit. When connecting a bonding wire, ensure that it is connected to bare
metal and never to a painted or non-metal surface. The wrist strap should be secure and in full contact with your skin, and
ensure that you remove all jewelry such as watches, bracelets, or rings prior to bonding yourself and the equipment.
Electrostatic discharge—ESD protection
ESD is a major concern when you handle electronic components, especially sensitive components such as expansion cards,
processors, memory DIMMs, and system boards. Very slight charges can damage circuits in ways that may not be obvious, such
as intermittent problems or a shortened product life span. As the industry pushes for lower power requirements and increased
density, ESD protection is an increasing concern.
battery.
Working inside your computer
37

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