Dell Precision 620 - Manual (Page 29)

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 40. System Board Removal
To remove the system board, perform the following steps:
1. Remove the computer cover .
2. Disconnect all cables from their connectors at the back of the computer.
3. Rotate the power supply out of the way.
4. Remove the MECs.
5. Remove the rear MEC bracket and system cooling fan.
6. Rotate the processor cover out of the way and remove the microprocessor/heat sink assembly .
7. Disconnect all cables from the system board.
See
Figure 28 for the location of system connectors.
8. Remove the AGP Pro card brace .
9. Remove all expansion cards .
10. Remove the screw that secures the system board to the bottom of the chassis.
11. Slide the system board toward the front of the chassis until it stops.
12. Carefully lift the system board out of the chassis (be sure to lift evenly and not twist the system board).
To replace the system board, perform the following steps:
1. Carefully place the replacement system board in the chassis.
2. Push down near each slot to engage the grounding clip onto its corresponding tab.
3. Push evenly on both sides of the system board as you slide and lock it into position (do not twist the system board).
4. Reinstall the mounting screw.
1 System board
2 Screw
CAUTION: Before you remove the computer cover, see " Precautionary Measures ."
NOTE: Before disconnecting any 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 the standby power LED, see
Figure 28 .