Number 220 - September 2001

Mysterious Turn-On
excerpted from Random Access by Bruce Preston Danbury PCUG, dacs.doc electric, July 2001
Q. I have a computer at work that seems to turn itself on from time to time. I go through "START/SHUTDOWN" to shut it off, but often it is turned on in the morning. I know that no one has touched it since I left. What's happening?     A. Newer PCs support a feature available on certain network cards and/or certain modems. For a network card, it is called "Wake On LAN" or abbreviated WOL; for a modem it is called "Wake On Ring." Essentially, if a machine has this option present (controlled via the BIOS SETUP) then if another machine in the local area network tries to access something on the 'shutdown' machine, the network	card will cause the machine to power up and boot. Similar situation for a modem. Our guess is that you have file or printer sharing available and some other machine in the network is trying to access a resource on the 'down' machine. If you have a centralized tape backup system, it could be causing the wake-up event. To turn this feature off, examine the BIOS settings and see if WOL or WOR are there--and if so, see if you can disable them. Alternatively, there is also a setting in the BIOS that controls the operation of the master power button on the front of the machine--on some it actually causes the machine to go into a 'sleep' or 'suspend' mode--to do a true power off you must hold the push button for four seconds. This can be changed so that the switch is a true power off.
Number 220 - September 2001