Sun Microsystems Ultra 20 User Manual page 106

4.5.12 Replacing the Motherboard
The following sections describe how to remove and install the Sun Ultra 20
Workstation system motherboard.
Note – The motherboard is not a CRU and should only be replaced by trained field
service technicians.
4.5.13 Removing the Motherboard
To remove the motherboard:
1. Turn off the power button on the back panel and all of the peripherals connected
to the workstation.
2. Remove the left-side access panel.
3. Gently lay the system on its right side on a stable, nonslip surface.
4. Remove any PCI cards installed on the motherboard (see
a PCI or Graphics Card" on page
5. Disconnect all cables attached to the motherboard.
6. Remove the eight Phillips screws that fasten the motherboard to the chassis (see
FIGURE 4-42
4-54 Sun Ultra 20 Workstation User Guide • August 2006
).
4-22).
Section 4.5.5, "Replacing