Removing The System Board Assembly; System Board - Dell PowerEdge 850 Installation And Troubleshooting Manual

System Board
The system board provides interface signal routing between the system board and the two SATA hard-drive bays, the optional CD drive, and the control panel.
In addition, the power supply is connected to the system board using two cables.
The system board and system board tray are removed and replaced as a single assembly.

Removing the System Board Assembly

CAUTION: Only trained service technicians are authorized to remove the system cover and access any of the components inside the system.
Before performing any procedure, see your Product Information Guide for complete information about safety precautions, working inside the
computer and protecting against electrostatic discharge.
1. Open the system. See "Opening the
2. Remove the cooling shroud. See
3. Remove the heat sink and processor. See
4. Remove the memory modules. See
NOTE: As you remove the memory modules, record the memory module socket locations to ensure proper installation.
5. Remove the fan module. See
6. If applicable, disconnect the optical drive interface cable from the daughter card connector PRI_IDE1. See Figure A-3.
7. Disconnect the two control-panel interface cables from the FRONT_PANEL connector on the system board and the USB_CONN connector on the daughter
card. See Figure A-3.
8. Disconnect the hard-drive interface cables:
a. If SCSI hard drives are installed, disconnect the interface cable from the controller card.
b. If SATA hard drives are installed, disconnect the interface cable from the SATA_0 and SATA_1 connectors on the daughter card. See Figure A-3.
9. Remove all PCI expansion cards installed on the riser card. See
10. Remove the riser card. See
11. Disconnect the chassis intrusion cable from the INTRUSION_SWITCH connector on the system board.
12. Disconnect the two power cables from the 12V and PWR_CONN connectors on the system board. See Figure A-3.
13. Loosen the captive screw that secures the system board tray to the chassis floor. See Figure 7-3.
14. Using the tab on the system board tray, slide the system board forward (toward the front of the system) and lift the assembly up and out of the
chassis. See Figure 7-3.
15. Lay the system board tray down on a smooth, nonconductive work surface.
Figure 7-3. Removing the System Board Assembly
System" in "Troubleshooting Your System."
"Removing the Cooling Shroud" in "Installing System Components."
"Replacing the Processor" in "Installing System Components."
"Removing Memory Modules" in "Installing System Components."
"Removing the Fan Assembly" in "Installing System Components."
"Removing the Riser Card" in "Installing System Components."
"Removing an Expansion Card" in "Installing System Components."