Microsoft KB Archive/833740

= The monitor does not turn on when you open the lid after you configure the energy-saving settings on a Windows XP-based portable computer =

Article ID: 833740

Article Last Modified on 10/19/2004

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APPLIES TO


 * Microsoft Windows XP Professional
 * Microsoft Windows XP Service Pack 1a
 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Service Pack 1a
 * Microsoft Windows XP Professional for Itanium-based systems

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Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
After you configure the energy-saving settings for an LCD monitor, the monitor on your Microsoft Windows XP Service Pack 1 (SP1)-based portable computer may not turn on again after you reopen the lid. For example, this problem may occur after you configure energy-saving settings by following these steps:
 * 1) Click Start, and then click Control Panel.
 * 2) In the Pick a Category window, click Performance and Maintenance, and then click Power Options.
 * 3) In the Power Options Properties dialog box, click the Power Schemes tab, and then click After 1 min in the Turn off monitor list.
 * 4) Click the Advanced tab, and then in the When I close the lid of my portable computer list, click Do nothing.
 * 5) Click Apply, and then click OK.
 * 6) Wait for one minute for the monitor to turn off. Close the lid of the portable computer, disconnect the computer from the power source, and then reopen the lid. The monitor may not automatically turn on as expected.

Note These steps apply when you have Control Panel set to Category View.

This problem is not resolved even after you press a key on the keyboard. In this scenario, you must restart your computer to regain use of the monitor.



CAUSE
This problem occurs because of an issue with the Videoprt.sys miniport driver and with the video graphics adapter (VGA) basic input/output system (BIOS) implementation in Windows XP SP1. When you open the lid of the portable computer in this scenario, the expected power request to turn on the LCD backlight does not occur.



RESOLUTION
To resolve this problem, obtain the latest service pack for Microsoft Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to obtain the latest Windows XP service pack



WORKAROUND
To work around this problem, add the following registry subkey:

To do this, follow these steps. Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.  Click Start, click Run, type regedit in the Open box, and then click OK. Locate and then click the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers

 On the Edit menu, point to New, and then click Key. Type LidCloseSetPower as the key name, and then press ENTER. Quit Registry Editor.</ol>

For additional information about how to work around this problem by using a registry subkey, click the following article number to view the article in the Microsoft Knowledge Base:

823348 INFO: The monitor may not turn on after you configure the energy-saving settings on some portable computers

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STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section. This problem was first corrected in Microsoft Windows XP Service Pack 2.

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MORE INFORMATION
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbbug kbfix kbqfe kbdriver kbwinxpsp2fix kbwinxppresp2fix atdownload KB833740

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