System Board - Dell Precision WorkStation 420 Service Manual

NOTE: Before disconnecting a peripheral from the system or removing a component from the system board, verify that the standby
power LED on the system board has turned off. For the location of this LED, see
CAUTION: There is a danger of the new battery exploding if it is incorrectly installed. Replace the battery only with the same or
equivalent type recommended by the manufacturer. Discard used batteries according to the manufacturer's instructions.
CAUTION: Before you remove the computer cover, see
To remove the system battery, perform the following steps:
1. If possible, enter System Setup and print the System Setup screens.
If the settings are lost while you are replacing the battery, you can refer to your written or printed cop of the system configuration information
to restore the correct settings.
2. To access the battery on the system board, rotate the power supply as described in
3. If installed, remove the CD-ROM drive according to the instructions in
access the battery.
4. Locate the battery and remove it.
The battery is mounted in a socket labeled "BATTERY" at the upper front-right corner of the system board (as you face the side of the
system) (see Figure 22).
NOTICE: If you pry the battery out of its socket with a blunt object, be careful not to touch the system board with the object.
Make certain that the object is inserted between the battery and the socket before attempting to pry out the battery. Otherwise,
you may damage the system board by prying off the socket or by breaking circuit traces on the system board.
5. Remove the system battery by carefully prying it out of its socket with your fingers or with a blunt, nonconducting object such as a plastic
screwdriver.
When you replace the system battery, orient the new battery with the "+" facing up. Insert the battery into its socket and snap it into place.

System Board

Figure 30. System Board Removal
To remove the system board, perform the following steps.
1 Battery
2 Socket
"Precautionary
"Diskette, LS-120 SuperDisk, Tape, or CD-ROM Drive
1 System board
2 Screw
Figure 22.
Measures"
"Rotating the Power Supply."
Removal" to