When powering on a Dell laptop PC, you may receive the following error message:
The AC adapter type cannot be determined. This will prevent optimal system performance.
Strike the F3 key if you don't want to see power warning message again.
Strike F1 key to continue, F2 to run the setup utility. Press F5 to run onboard diagnostics.
Or Unknown or incorrect AC adapter detected.
The Dell laptop PC will continue to power on after pressing F1 key, however the error message is repeated every time the PC is turned on. The PC may exhibit symptoms such as sluggish performance, battery does not charge or AC adapter error message within Microsoft Windows operating system.
AC adapter error messages can be caused by any of the following:
Expand the sections below for more information on how to troubleshoot AC adapter error messages.
AC adapter cable and power cables may get frayed, cut and wires exposed at either end of the cables. This may be due to the way the cable is wrapped around the AC adapter or if the cable is subject to undue stress. If the damage is severe enough to expose wires, you should discontinue using the AC adapter. To check the AC adapter, cables and adapter port on the laptop for any damages:
For more information, refer to the Dell knowledge-base article AC Adapter Damage.
If there are damages found, contact Dell Technical Support for replacement options. If there are no damages found, proceed to the next step.
If the wall outlet is working correctly, proceed to the next step.
Once the residual power has been drained, if the PC does not power on with the AC adapter, proceed to the next step.
Once the power cable and AC adapter cable is disconnected and reconnected, proceed to the next step.
Reset the AC adapter by following these steps:
If the AC adapter LED indicator is on, proceed to the next step.
If the AC adapter LED indicator is off or turns off when connected to the PC, contact Dell Technical Support.
Using an AC adapter that has a lower wattage may show an error message "The AC adapter type cannot be determined. This will prevent optimal system performance" or "Unknown or incorrect AC adapter detected", reduce the processor (CPU) speed to run slower to save power, laptop battery might not charge or charge slowly or AC adapter might heat up.
Dell laptop PCs may use either a 65W (Watt), 90W, 130W, 180W or 240W AC adapter. For optimal performance, use the AC adapter that came with the Dell laptop PC. AC adapter's wattage information is printed on the label which is located at the bottom of the AC adapter.
To verify if the PC is recognizing the AC adapter correctly:
Running a hardware diagnostic test can help you identify what the issue may be and provide you troubleshooting steps to help resolve the issue. Dell offers both built-in and online diagnostics. Dell ePSA hardware diagnostic test will help check if the AC adapter is recognized correctly.
To run the Dell ePSA built-in hardware diagnostics:
For more information on running a hardware diagnostics on a Dell PC, refer to the Dell knowledge-base article Resolve Hardware Issues With Built-in and Online Diagnostics (ePSA or PSA Error Codes).
BIOS is a firmware that is embedded onto the System Board of your computer. Updating the BIOS to the latest version may help the PC recognize the AC adapter. Updating the BIOS to the latest version requires the laptop PC to be powered by the AC adapter and battery.
To update the BIOS to the latest version, refer to the Dell knowledge-base article How do I download and install the latest BIOS for my Dell computer?.
If the AC Adapter Type is not recognized by the PC, refer to the Dell knowledge-base article Forcing a BIOS Update without the AC adapter attached on a Dell Laptop. Before forcing the BIOS update, please read the disclaimer below.
Can't Turn On Your Laptop - (01:46)
Care for Your AC Adapter - (00:41)
Article ID: SLN148385
Last Date Modified: 08/08/2018 10:38 AM
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