When AC Power Is Disconnected from a Portable Computer the Screen Goes Blank (293391)



The information in this article applies to:

  • Microsoft Windows Millennium Edition
  • Microsoft Windows 98 Second Edition
  • Microsoft Windows 98

This article was previously published under Q293391

SYMPTOMS

When you are using a portable computer on AC power and the power cord is unplugged, the screen may go blank. When you press a button on the keyboard or move the mouse, the screen comes back on.

CAUSE

The Power Management tool in Control Panel contains System standby, Turn off monitor, and Turn off hard disks options for Power Management. For each of these options, you can set the length of time that the computer must be idle before the action is performed if your computer is on battery power or is plugged in to AC power.

If your computer exceeds the time for battery power to turn off the monitor, but has not exceeded the time for this action to occur on AC power, the screen goes blank when you unplug the power adapter. This occurs because the time limit for battery power is enforced as soon as the computer is unplugged, and the current monitor timer is not reset (although the System standby and Turn off hard disks option's timers are reset).

After the screen goes blank, if you perform some action to resume the monitor (for example, use the mouse to click, or press a key), the screen immediately comes back on.

STATUS

This behavior is by design.

MORE INFORMATION

This behavior saves power. This behavior does not occur with the other two Power Management options (System standby or Turn off hard disks) and does not create any adverse effects on the computer or interrupt any programs that are running.

Modification Type:MinorLast Reviewed:12/20/2004
Keywords:kbenv kbHardware kbnofix kbprb KB293391