IBM x3400 7975 Problem Determination And Service Manual page 91

13. Toggle the boot block recovery switch to 1.
14. Replace any adapters that you removed (see "Installing an adapter" on page
103); then, install the side cover (see "Installing the side cover" on page 101).
15. Lock the side cover if it was unlocked during removal.
16. Reconnect the external cables and power cords; then, turn on the attached
devices and turn on the server.
The following table describes the function of each switch on the system board.
Table 4. System board switches
Switch number
1
2
Description
Boot block:
v When this switch is on 1, this is normal mode.
v When this switch is toggled to On, this enables the
system to recover if the BIOS code becomes damaged.
Clear CMOS:
v When this switch is on 2, this is normal mode. This
keeps the CMOS data.
v When this switch is toggled to On, this clears the CMOS
data, which clears the power-on password and
administrator password.
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Chapter 2. Diagnostics