Computer will not automatically reboot after UPS has shutdown and restarted

Issue:
The computer will not automatically reboot after the UPS has shut down and restarted

Product Line:
PowerChute Personal Edition
PowerChute Business Edition
PowerChute Serial Shutdown
PowerChute Network Shutdown

NOTE:
Like any other software application, PowerChute cannot run when the OS is off, so it cannot restart the OS.


Environment:
All devices that include a BIOS
All APC UPS

Cause:
This problem is independent of the type of UPS connected. It is a function of the BIOS implementation supporting the soft-switch on computers. It is not a problem with APC UPSs or with PowerChute.

Solution:

To resolve this, change the BIOS setting to Always On, if possible. If you cannot modify this setting, then the UPS will not be able to automatically reboot the computer under any circumstances, with APC or any other UPS.

Please contact your computer manufacturer to find out if it is possible to change this BIOS setting on your particular computer and for exact instructions on how to do so.

Background:

Most new computers on the market today use an ATX motherboard, which supports a soft switch to turn the Computer On and off. The implementation of this soft switch includes a BIOS parameter that defines the state the computer will enter when the power supply senses input power when plugged into the wall. This BIOS parameter can have any one of three values :

ALWAYS ON: When power is cycled on, the computer will automatically turn on and boot up.

ALWAYS OFF: When power is cycled on, the computer will stay off until the user manually hits the On/Off soft switch.

LAST STATE: When power is cycled on, the computer will either come on or stay off depending on whether it was On or Off when the power was lost.

Most computer manufacturers set this parameter to Last State, and some computer manufacturers set this parameter to Always Off. It is highly unlikely to find the parameter set to Always On.  In many cases, the computer manufacturer allows the user to change this parameter via the system setup menu, which can be accessed before the operating system loads when the computer is turned on.

If this parameter is set to Always Off, then an APC UPS cannot reboot this computer as it will not turn on when the power is cycled, independent of the state of the PC prior to power being turned off.

Publié pour: Schneider Electric Belgium