How to Test Power Management Hardware on a Laptop - dummies

How to Test Power Management Hardware on a Laptop

By Dan Gookin

You can test your laptop’s power management hardware. However, bear in mind that if you find a power management issue, you have to turn over the laptop to the manufacturer (or wherever) to get it fixed. But at least you will know that the problem with your laptop really needed the services of a professional when you get the bill.

The laptop’s ACPI hardware has its own BIOS, which means that, like other BIOSes in the system, it does its own testing and diagnostics when you first start the machine. So the first place to look for power management hardware trouble is the PC’s start-up screen, where you may find various power management, or ACPI, start-up error messages.

Another way to test the power management hardware is to use the System Information utility. Because some laptop manufacturers poorly implement the ACPI standard, conflicts may occur that the System Information utility would detect. Follow these steps:

  1. From the Start menu, choose All Programs→Accessories→System Tools→System Information.

  2. Click the plus sign (+) to expand the Hardware Resources list on the left side of the System Information window.

  3. Choose Conflicts/Sharing.

    You see a list of items displayed.


    The items in the list are both conflicts and sharing. What you probably see are shared hardware resources, which aren’t a problem. But:

  4. Scan the list for any mention of power management hardware ¯ specifically, the acronym ACPI.

    Finding something wrong with the ACPI hardware merely confirms your suspicion. Again, there’s no way to fix the problem, especially by using the System Information window.

  5. Close the System Information window.

Hardware issues, especially IRQ conflicts, aren’t as prevalent in today’s laptop hardware as they once were, and then primarily with PC desktops loaded with expansion cards. Even so, checking the System Information display may explain why you’re having power management issues.

For example, if the power management hardware is being shared with an internal modem, you may notice power management issues when the modem is being used. That’s the type of conflict the System Information window highlights. Resolving the issue involves reconfiguring the conflicting hardware, which might be possible in the BIOS/Setup program.

Troubleshooting power management issues in Safe mode is difficult. That’s because the power management software isn’t loaded in Safe mode, which means that even if the power management hardware is broken, you have no way to test it.