Why Does My AC Adapter Not Work with the Laptop?

Last updated: December 15, 2022 at 12:22 pm

Do you need to power up your laptop? Maybe it’s time to check your AC adapter. Remember that the adapter plugs into the wall current at one end of the computer at the other—in between is a covered box converting 100 to 240 volts of alternating current to approximately 15 to 20 volts of direct current.

If your adapter and cords are working correctly, the computer will receive enough power, and its battery will not recharge. Fortunately, you can easily buy a replacement adapter from manufacturers or third-party sources. 

What is an AC Adapter?

Known as an AC adapter, AC converter, or charger, an AC adapter is an external power supply utilized with devices running on battery or doesn’t have a power source.

AC adapters help lessen a laptop computer’s size by eliminating the need for a standard-sized power supply. It comprises a central unit drawing power from an AC outlet. Then, it converts power to DC, which the computer uses, and the second cord plugs into it.

Every AC adapter has a particular power rating, measured in watts or volts that it can handle and output to an electronic device. The type of plug and power rating isn’t universal. Thus, you can only use the AC adapter with devices with the same connector and requirements.

You can use a universal AC adapter designed to work with numerous devices of different sizes and types of plugs for connecting to such devices. Further, a universal AC adapter may have a wattage or voltage range, such as 70 watts to 125 or 100 volts to 240 volts. That enables a higher range of compatible devices. 

What’s the Function of an AC Adapter? 

AC adapters convert the 120-volt AC power from the wall outlet to a smaller DC power for your electronic device. They achieve that in two steps: scaling the voltage and converting the AC to DC. 


Did you know that your AC adapter scales the 120 volts from your wall down to a voltage in an area of 6-18 volts via a small transformer? Often, a transfer includes two coils of wires scattered around an iron core. 

The ratio of the coil number that turns into one wire to the other is equivalent to the ratio of the voltages in the two wires.


Once converting the power to the desired level of voltage, the adapter converts the AC to DC with a rectifier. It uses a combination of diodes to make constant DC power from alternating AC power. 

What Are the Possible Reasons for an AC Adapter to Fail?

Keep in mind that all things electronic have a limited life. They will fail eventually. They may get dirty power that stresses the components. They also heat up and cool down every time you use them, not to mention internal components may rust. With luck, your AC adapter will not reach its final moment of mortality before the laptop retires. 

More reasons why your AC adapter fails include:

  • The removable plug could break, or the cable could become shorted out or cut. Do not try to use the electrical device with apparent damage. That’s especially true on the AC side of your adapter. It’s easier to buy a replacement cable than to replace your entire house and belongings if you do something silly and burn it down. 
  • The connection between the wall socket and the converter might need to be fixed.
  • The cable from the converter to your laptop could come from the device itself. That’s one simple. You can easily reattach the plug. 
  • The converted in the sealed box could be fried from a power surface from your AC line. 

How Can you Troubleshoot Your AC Adapter Problems?

Are you experiencing an issue where your laptop’s AC adapter is not working correctly? You can do several things before planning on buying a new adapter. This section covers the best troubleshooting tips you can do.

Update the BIOS 

The BIOS is firmware embedded into your laptop’s motherboard. Updating it to the newest version will help the device recognize the AC adapter properly. 

Remember that laptops should have their battery installed and connected to the AC adapter before updating the BIOS. Also, other laptops should have at least a ten percent battery before you start the update. 

If your battery is less than ten percent, you can force the BIOS to update from the DOS environment. But a failure during that process will cause permanent damage to the computer’s system board. Always proceed with your own risk. 

Run an ePSA hardware diagnostic test 

Did you know that running a hardware diagnostic test could help determine the problem and offer you troubleshooting steps to fix the problem? A pre-boot assessment checks if the system board acknowledges your AC adapter properly. 

Here are the steps you should take:

  • Turn off your computer. 
  • Tap F12 a few times until you notice the One Time Boot Menu.
  • Use the arrow keys to click Diagnostics and press Enter
  • Follow the proper on-screen instructions to finish the diagnostic test.
  • If there is an error, ensure you note the error and validation codes. Call your laptop technical support to understand more about the repair options available in your area.
  • If the diagnostic test passes, it indicates there are no hardware problems. 

Confirm the wattage of your AC adapter 

Using an AC adapter with a lower wattage might cause one of the following problems: 

  • The AC adapter heating up
  • The laptop battery doesn’t charge or charges slowly 
  • The laptop may minimize the CPU speed to save power
  • The laptop may present an error message, like “Unknown or incorrect AC adapter detected” or “The AC adapter can’t be determined. It will prevent optimal computer performance.” 

Every laptop uses an AC adapter of different wattages. That could depend on your laptop’s hardware configuration. Also, laptops come with 240 watts, 180 watts, 130 watts, 90 watts, 65 watts, and 45 watts AC adapters.

For optimal performance, you should use the original AC adapter that comes with your unit. You can find the wattage information of your AC adapter on the label located at the bottom of your AC adapter. 

To confirm if your laptop recognizes its AC adapter properly, do the following:

  • Restart your computer
  • When the logo appears, hit the F2 key until the message Entering Setup shows.
  • Confirm the AC adapter type in your BIOS options. You can find the information on your AC adapter on the BIOS’s main screen. If your AC adapter type is NONE, confirm that it’s linked to the computer, the correct AC adapter is linked to the laptop, and the LED light indicator on the AC adapter is ON.
  • If the AC adapter type is Unknown, you can try using another AC adapter. If the problem persists or the same AC adapter is working on another laptop, it’s time to call your technical support team. 

Check the LED indicator on your AC adapter 

Make sure you reset the AC adapter by following the following steps:

  • Unplug the AC adapter from your wall outlet for about fifteen seconds.
  • Unplug your AC adapter from your computer.
  • Plug the adapter into a good-known wall outlet.
  • Plug the adapter into your device.
  • Check the LED indicator on your AC adapter.

You can find the LED indicator either on the adapter (DC) plug or the AC adapter brick. If the LED indicator on your AC adapter turns on, continue to the next step. 

However, if your AC adapter’s LED indicator is off or turns off when it’s connected to the laptop, contact a technical support team to understand more about the repair options available in your area.

Disconnect and reconnect the AC adapter and power cable

Here’s what you need to do:

  • Unplug your AC adapter from the wall outlet.
  • Unplug the adapter from your computer.
  • Disengage the power cable from your AC adapter. 
  • Firmly connect your power cable to the AC adapter.
  • Confirm if the LED on your AC adapter is on. If the LED isn’t turning on, try a compatible AC adapter.

If applicable, connect to the proper USB-C power port 

Did you know that USB-C is a standard cross-platform connector for charging, transferring data, and connecting devices? Pick laptops that use a USB-C port to power and charge your device. 

Make sure you connect the USB-C charger to the proper USB-C port that supports charging, particularly on a laptop with more than one USB-C port. 

Drain the remaining power 

If you want to drain the residual power of your laptop, here’s what you must do:

  • Unplug your AC adapter from the wall outlet. 
  • Separate any devices connected to the laptop.
  • Remove the laptop’s battery. Check the user manual of your laptop for further instructions on how to detach the battery. If your unit has a non-removable battery, you can skip this section. 
  • Press and hold its power button for about thirty seconds to drain the remaining power from your device.
  • Connect the battery.
  • Plug your AC adapter into the laptop and wall outlet.
  • Turn on your laptop. 

Once you drain the residual power, but your laptop still doesn’t turn on with your AC adapter, you can proceed to the next step. 

Check if the wall outlet is properly working 

  • Unplug the AC adapter from your wall outlet.
  • Connect another device to your wall outlet to confirm if your wall outlet is properly working.
  • Connect your AC adapter to a good wall outlet.
  • Plug the AC adapter into your wall socket. You can bypass power regulators, such as power splitters, UPS, or surge protectors. Doing so will help isolate problems with the power regulators.

Is your AC adapter connected to a docking station? Connect the AC adapter straight to your device to confirm if the AC adapter is properly working. 

But what if the AC adapter works fine after your bypass the docking station or power regulator? The problem can be with that specific device. Go to the next step if your AC adapter doesn’t turn on.

Check your cables, AC adapter, and the DC-in port on your laptop for potential damages

The power cable and AC adapter cable can get cut or frayed. The wires may also become uncovered at either end of the cable. That may occur because of how the cable is wrapped around your AC adapter or when the cable is subject to constant stress.

Is the damage severe enough to expose the wires? Immediately stop using the AC adapter. Here’s what you can do to check the cables, AC adapter, and adapter port for potential damages:

  • Unplug the AC adapter from your wall outlet.
  • Detach the AC adapter from your laptop.
  • Check the cables and AC adapter for any signs of overheating or physical damage.
  • Check if the pin inside the adapter port or plug is damaged, broken, or bent. 

Consider Replacing Your AC Adapter? 

Do you determine that your AC adapter is not working? Do you need it to replace? You can get a replacement from your laptop manufacturer.

Make sure you buy a universal AC adapter from a trusted local or online electronics retailer. One brand to consider is Prowin Power, a quality AC adapter manufacturer, and it is a popular choice.

We make numerous universal AC adapters for most laptop models and brands. Ensure you buy one that matches the specifications of your current AC adapter, including the amperage and the voltage. On top of that, check the packaging to ensure it works for your laptop model and brand. 

If you need help with your AC adapter, contact us now. We are your one-stop power solution supplier. Reach out to get started!

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