Dell PowerEdge SC 420 - Manual (Page 15)

6. Remove the processor. See " Replacing the Processor " in "Installing System Components."
7. Using a #2 Phillips screwdriver, remove the captive screw that secures the system board tray to the chassis. See Figure C -5 .
Figure C-5. Removing and Installing the System Board
8. While pulling up on the system board tray release tab, slide the tray toward the front of the system and then remove the system board tray from the
system.
9. Place the system board tray on a flat nonconductive surface.
Installing the System Board
1. While lowering the system board into the chassis, align the I/O connectors with the opening in the back panel.
2. Slide the system board backward until the system board snaps into place.
3. Using a #2 Phillips screwdriver, install the screw that secures the system board tray to the chassis. See Figure C -5 .
4. Install the processor. See " Replacing the Processor " in "Installing System Components."
5. Install the memory modules in the same sockets that they were removed from. See " Installing a Memory Module " in "Installing System Components."
6. Install the expansion cards and connect any cables. See " Installing an Expansion Card " in "Installing System Components."
7. Connect the following cables to the system board. See Figure A -3 in "Jumpers and Connectors":
l Two power-supply cables from the POWER connectors
l If applicable, diskette data cable from the FLOPPY connector
l I/O panel cable from the FRONT PANEL connector
l 5.25-inch device data cable from PRI IDE connector
l Cooling fan from the CPU_FAN connector
NOTE: Record the memory-module socket locations to ensure proper reinstallation of the memory modules.
NOTICE: The processor and heat sink can become extremely hot. Allow sufficient time for the processor and heat sink to cool before handling.
NOTICE: To prevent damaging the processor, do not pry the processor off the heat sink.
NOTICE: Use caution when removing and installing the processor. Bending or damaging the processor socket pins will permanently damage the system
board.
NOTICE: To prevent damaging the processor, clean the heat sink to remove any thermal grease and then apply fresh thermal grease to the processor
before installing the heat sink.