Sun Microsystems Sun Fire X4100 - Manual (Page 58)

2-32 Sun Fire X4100 and Sun Fire X4200 Servers Service Manual • June 2006
Note – If you do not remove the P5 jumper, the server will force a recovery of the
new BIOS every time that you power cycle the server.
2.6 Using the Clear CMOS Jumper
TP51/TP52
You can use this jumper to clear the server’s CMOS settings in the case of a system
hang. For example, if the server hangs because of incorrect settings and will not
boot, use this jumper to invalidate the settings and reboot with defaults.
1. Shut down the server to standby power mode by using a ballpoint pen or other
stylus to press and release the recessed Power button on the front panel.
See Section 2.2, “Powering Off the Server” on page 2-3 .
2. Disconnect the AC power cords from the server.
Caution – Before handling components, attach an ESD wrist strap to the grounding
post that is built into the rear of the chassis (see FIGURE 1-2 or FIGURE 1-5 for the
location). The system’s printed circuit boards and hard disk drives contain
components that are extremely sensitive to static electricity.
3. If the server is in a rack, slide it far enough from the rack so that you can remove
the main cover. If you cannot safely view and access the motherboard, remove the
server from the rack.
4. Remove the main cover from the server.
See Section 3.2.2, “Removing the Main Cover” on page 3-3 or Section 4.2.2, “Removing
the Main Cover” on page 4-3 .
5. Install the shorting jumper across the TP51/TP52 header pins.
See FIGURE 2-4 for the TP51/TP52 jumper location.
6. Wait 10 seconds, then remove the shorting jumper.
This jumper removes battery power from the SouthBridge chipset where the CMOS
settings are stored, thereby removing the CMOS settings.
7. Reinstall the main cover to the server.
8. Reconnect AC power cords to the server.
The server powers up to standby power mode, indicated when the Power/OK LED
on the front panel is flashing.