Jumper Settings; Clear Cmos - Beckhoff CB1056 Manual

Chapter: Connectors

Jumper Settings

3.5 Jumper Settings

3.5.1 Clear CMOS

In case the board doesn't start up anymore and BIOS setup is inaccessible there is a "last resort": You can
use the "Clear CMOS" jumpers to reset all CMOS settings to factory defaults. In order to do so you need to
shut down the computer, change the jumper settings from normal (pins 1 & 2 short) to "Clear CMOS" (pins
2 & 3 short) first on jumper Clear CMOS 1 and then on jumper Clear CMOS 2, wait a few seconds, put the
jumpers back into normal position and reboot.
C
AUTION
In order to avoid an undefined system state it is essential to ensure that the shorting of jumper Clear CMOS
1 (J1800) takes place BEFORE and only combined with the shorting of jumper Clear CMOS 2 (J1801).
Furthermore please notice, that if you reset the CMOS this does not only bring all settings made in BIOS
setup back to default values, it also clears the date and time information stored in CMOS. So don't forget
that, after the Clear CMOS procedure, you will have to set the clock again.
page 50 Beckhoff New Automation Technology CB1056