Power management options on laptops often create problems for users. To aid you in your troubleshooting efforts, Faithe Wempen created a comprehensive checklist on such user complaints and offers some solutions to those vexing problems.
Hibernate and Standby modes are extremely useful to battery-hungry laptops. Unfortunately, many users are unaware of the different settings involved in configuring a laptop to properly use these features. If you support laptop users, you know all too well the trouble these modes can cause. To help you troubleshoot such issues, I've compiled some common end-user complaints about laptop power management along with some possible solutions.
Hibernation is the procedure in which the content of memory is saved to disk before shutting down so when the computer wakes up again, you don’t have to go through a full restart. Standby places the computer in a low power consumption mode, using only enough power to preserve the content of RAM, so the computer can wake up quickly without a full restart.
Won't wake up from Standby or Hibernation
User complaint: "After placing the computer in Standby or Hibernate mode, it appears completely dead. The key(s) that are supposed to wake the computer up do not have any effect."
Troubleshooting tips: In the short term, here are some ways to try to regain control of the PC:
- Be patient. Some PCs take up to 30 seconds to wake up.
- Look for a Suspend or Hibernate key. Some laptops have special keys or buttons for one or both, but the user might not have noticed them if he normally uses some other wake-up method.
- Try pressing and holding the PC’s power button for five seconds or more. On a PC that's configured to Suspend or Hibernate with a press of the power button, holding down the power button will usually reset and reboot it.
- Most laptops have an [Fn] key you can press in conjunction with other keys to control laptop-specific features, including power management.
- As a last resort, remove all batteries, wait a few minutes, and then replace the batteries.
After you successfully restart the PC, you need to look for the underlying problem. Typically, such problems stem from a disagreement either between the power management features of the BIOS and those of your Windows version or between power management and the video card. To begin troubleshooting, make sure you have the most recent version of the video driver installed. It never hurts to go ahead and download and install the latest drivers from the manufacturer's Web site. Outdated video drivers have been known to cause power management problems in some systems.
A conflict between the BIOS power management and Windows power management is the most common cause of such wake-up failure. Experiment with different settings in the BIOS to see if that might solve the problem. For example, a PC might not wake up if Advanced Power Management (APM) is enabled in the Power Options of Control Panel, the BIOS is configured to suspend the computer, and the BIOS time-out value is less than the value configured in Windows. To correct this, you would set the BIOS time-out to be higher than the Windows time-out.
Because of the power management issues I mentioned, Microsoft recommends that all BIOS-based power management be disabled on PCs running Windows NT 4.0.
If tweaking the BIOS and Windows power settings doesn’t help, try visiting the PC manufacturer’s Web site to see if a BIOS update might be available. There are known issues with some PCs failing to resume from Standby, which can be corrected by updating the BIOS.
BIOS can support both APM and Advanced Configuration and Power Interface (ACPI) power management standards, but ACPI is the more recent and more sophisticated standard. By upgrading the BIOS, you can add ACPI support to the computer, and doing so can potentially clear up compatibility problems between APM and your hardware or OS. If you continue to have wake-up problems and you can’t upgrade from APM to ACPI in your BIOS, try disabling APM entirely in the BIOS.
There’s an APM diagnosis tool, Apmstat.exe, in the Support/Tools folder on the Windows 2000 CD-ROM. Use the -v switch, which stands for Verbose, to get more data.
If you can’t solve the problem from the BIOS, try attacking it from the Windows side. Experiment with Windows Power Management settings to see if changes to any of them resolve the issue. Remember, you don’t necessarily have to use the Windows interface for Standby or Hibernate if your BIOS can directly support it. On one laptop I worked on, the client finally had to forego the Windows power management and use the Hibernate feature built into the BIOS by pressing the PC’s power button.
USB device won't wake PC up
User complaint: "An external USB keyboard or mouse is attached to the laptop, and Windows is configured to wake up from Hibernation or Standby on key press or mouse movement. However, it will not do so."
Troubleshooting tips: In Windows 9x/Me, laptops using USB devices to activate a wake up can only use the Suspend state (S1 state). Such USB devices can't be used to wake up a laptop from Hibernation (S4 state). If you are attempting Hibernation, set Power Management to wake up from Hibernation using some other signaling method, such as the PC’s power button.
If you are attempting Standby mode, such problems can occur if you have removed and reinserted a PC card since you last restarted the PC. It’s a known bug, and there's not much you can do about it other than to do a complete reboot after you remove and reinsert a PC card and then attempt to use Standby mode.
Lockup when entering Standby or Hibernation
User complaint: "When attempting to place the computer in either Standby or Hibernate mode through Windows, the computer locks up and shows either a black screen and flashing cursor in the corner or the Windows desktop."
Troubleshooting tips: This usually indicates a video adapter problem. Try a different video card driver; make sure you have the latest one from the manufacturer’s Web site. If the problem occurs only when using Hibernate but not Standby mode, you might simply have to resort to not using Hibernate on that computer.
The problem can also result from a COM port being open on some Dell or IBM laptops using Windows 2000. If you have an open connection through a COM port, such as to a modem or handheld device, close it before entering Standby mode.
Black screen or errors when resuming after Hibernation
User complaint: "After resuming from Hibernate, Windows doesn’t work right. For example, the Start menu might not work anymore, the screen might be totally black, or I get blue-screen errors."
Troubleshooting tips: This is a known bug that occurs on laptops with PCI or AGP video cards using the generic VGA video driver that comes with the OS. The generic VGA video driver doesn’t support Hibernation. You might also see this error with other video drivers, too, especially on laptops that use off-brand video drivers that don't support APM or ACPI. With some Windows versions, there is also an issue with older video drivers not written specifically for that version. For example, using a Windows NT version of a video driver in Windows 2000 could cause a black screen on wake up or no wake up at all.
If possible, switch to a newer video driver or one designed specifically for the video card. If you can't update the driver, you won’t be able to use Hibernate on this PC, so go into Power Management in the Control Panel and turn off Hibernation support.
If you need to know how to contact your video adapter manufacturer, check the Microsoft Product Support Services' Hardware and Software Third-Party Vendor Contact Lists: A through K L through P Q through Z
STOP error when entering or resuming from Standby or Hibernate
User complaint: "In Windows 2000, I receive a 'STOP 0x0000009F DRIVER_POWER_STATE_FAILURE' error message when entering or exiting Standby or Hibernate mode." Or, "In Windows 2000, when entering Standby mode or resuming laptop use after Standby mode, I see a blinking cursor in the top left corner and the message, 'NMI: Parity Check/Memory Parity Error.'"
Troubleshooting tips: Both of these complaints are usually the result of a noncompliant device driver. In an older laptop that has been upgraded to Windows 2000 from an earlier OS version, noncompliant device drivers are often an issue. Make sure you have up-to-date, signed drivers for all hardware components in the PC. Use the executable file Sigverif.exe to verify the signatures. Also check the Hardware Compatibility List to ensure that all hardware is supported by Windows 2000. Reinstalling Windows 2000 into a different folder can also correct this problem, because it forces Windows to install fresh drivers for all hardware.
Standby is not on the Shut Down menu (Windows 98/Me)
User complaint: "I want to activate Standby through Windows with the Start/Shut Down command, but Standby isn’t one of my options."
Troubleshooting tips: If Standby locks up your computer two times in a row, a message appears asking whether or not you want to disable the feature. If you answer Yes, Standby won’t be an available option at shut down. Standby mode will also be missing if the PC is not APM compatible.
If Standby mode is off but you think the PC is actually capable of using it, you can turn it back on. To do so, remove Advanced Power Management Support from the Device Manager and then restart the PC to let it detect APM support. If that doesn’t work, try removing your floppy disk controller from Device Manager and letting Windows detect APM support upon restart. When the system detects APM support, Windows will reset the SuspendFlag entry in the Registry. If that step doesn’t work, you’ll need to edit the Registry directly. Look for this key:
There should be a Flags value and a SuspendFlag value. If there isn’t, you’ll need help from the hardware manufacturer. If the Flag's value is greater than 200, modify it by subtracting 200 from its current value. Set SuspendFlag to 0 if it is not already set to that value.
Be careful when editing the Registry. Any changes you make are saved immediately.
A program or device prevents Standby
User complaint: "Windows won’t enter Standby, and one of these two messages appears: 'Your computer cannot go on Standby because a device driver or program won't allow it. Close all programs and try again' (Windows 98/Me) or 'The system cannot go to Standby mode because the driver <drive>\<device driver name> failed the request to Standby' (Windows 2000). I have closed all open programs, but the message persists."
Troubleshooting tips: Some programs or devices—particularly those with outdated drivers or drivers that aren't ACPI compliant—can cause this error to occur. If you have trouble determining which program is causing the problem, try the Windows Power Management Troubleshooter, which is available as free a download from Microsoft. It is written specifically for Windows 98 but may be of some use in other versions, as well. Also, look for a file called Nohiber.txt in the main Windows folder in Explorer. If present, it will give you clues about which device is preventing the laptop from entering Hibernation or Standby mode.
You can also look for the errant device on your own. For example, some models of Epson USB printers, as well as several models of multifunction devices (particularly those that listen for incoming faxes), have been known to prevent a PC from entering Standby mode. Try disconnecting all USB devices and removing all PC cards one at a time as part of your troubleshooting process. Also, if the USB devices don't automatically disappear from Device Manager when disconnected, try manually disabling all USB devices in Device Manager. Also, investigate whether or not there might be any built-in devices disabled. For example, there are known issues of Intel network cards interfering with Standby mode when they have been disabled in Device Manager.
A few devices have no workaround and cannot coexist with Standby or Hibernate mode. Some versions of the Tseng Labs ET-4000 video adapter under Windows 2000 are like that. On laptops using such devices, you cannot use Windows-based Standby or Hibernate modes; however, you might try the OS-independent BIOS power management, if available.
Although it is seldom an issue on laptops, the use of Internet Connection Sharing (ICS) in Windows 98/Me can also prevent a computer from going into Standby or Hibernate mode. This behavior is designed to prevent the computer serving the Internet connection from disconnecting others in the workgroup who might be using the connection. For the same reason, The Turn Off Monitor and Turn Off Hard Disks power management options also do not work on the host Internet sharing computer.
Doesn't enter Standby or Hibernation at correct time
User complaint: "I set up the power options in Windows to make the computer enter Standby mode after a specified period of inactivity, but it doesn’t do so."
Troubleshooting tips: One common cause of this error is using an OpenGL type screen saver. Try using a different screen saver or turning off the screen saver feature altogether.
Turning on Hibernation makes Standby trigger randomly
User complaint: "After enabling Hibernation support, the computer will spontaneously put itself in Standby mode at random intervals even though Standby is set to Never in the Control Panel."
Troubleshooting tips: This is a known bug on certain laptops running Windows 98 Second Edition. To fix the problem, turn off Hibernation, and then set Standby to any value except Never in Power Management. Do this for each power scheme. Then you can turn Hibernation back on.
Can't Hibernate or Standby with 64MB of RAM or less
User complaint: "On a laptop with limited RAM, generally 64 MB or less, the computer will sometimes not enter Hibernation or Standby mode. It starts to do so, but the Windows desktop comes back instead."
Troubleshooting tips: This problem occurs when all the conventional memory is in use (below 640 KB) and the PC is relying on virtual memory. Try shutting down all unnecessary programs before entering Hibernation or Standby. Adding more physical memory to the PC will also help.
Battery alarm doesn't sound in Standby
User complaint: "The computer is set to enter Standby when the low battery alarm is triggered and to shut down when the critical battery alarm is triggered. However, once it goes into Standby, the critical alarm does not trigger, and the computer eventually runs out of battery power and loses all unsaved work."
Troubleshooting tips: The problem is that Windows can’t do anything while it’s in Standby mode, including reporting any alarms. To solve this problem, set the low power alarm to sound an alarm or display a message rather than going into Standby. You can then set the critical alarm to Hibernate or shut down.
The fixes I discussed should give any IT support technician a solid foundation in troubleshooting problems encountered when using the Hibernate or Standby modes. However, if none of these fixes solve your problem, you can always try searching the Microsoft Knowledge Base. For Windows 2000 systems, a good starting place is article Q266169, "How to Troubleshoot Problems with Standby Mode, Hibernate Mode, and Shutting Down Your Computer in Windows 2000." For Windows 98/Me systems, check out the Windows 98 and Windows Me Hardware/Device Driver Troubleshooting Resource Center.