How to Troubleshoot Power Issue on a Dell Desktop or All-in-One

Most often, restarting the computer resolved many issues. The residual power in the computer may cause the laptop not to turn on. Follow the steps below to drain the residual power.

1. Turn off the computer. Press and hold the power button for 10-15 seconds.
2. Disconnect the power cable from the computer.
   NOTE: Dell all-in-one computers may either come with a power cable or an AC adapter. Disconnect the power cable or the AC adapter depending on the configuration of the computer.
3. Disconnect all devices or devices like USB drives, printer cables, and media cards (SD/xD).
4. Press and hold the power button for 15-20 seconds to drain residual power.
5. Connect the power cable to the computer.
6. Turn on the computer.

If this did not resolve the issue, go to the next step.

The power cable, AC adapter cable, and power cables may get frayed or cut, and wires may become 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 power cable or AC adapter. To check the power cable, AC adapter, cables, and the power port on the desktop or all-in-one for any damages:

1. Unplug the power cable or AC adapter from the wall outlet.
2. Unplug the power cable or AC adapter from the computer.
3. Check the power cable or AC adapter and cables (including the power cable) for signs of physical damage or overheating.
4. Check if the pin inside the plug or adapter port is bent, broken, or damaged.

If you notice a damage, contact Dell Technical Support for repair options. If you do not find any damage, go to the next step.

1. Unplug the power cable or AC adapter from the wall outlet.
2. Connect another device on the wall outlet to verify if the wall outlet is working correctly.
3. Try a known-good wall outlet.
4. Plug the power cable or AC adapter directly to the wall outlet.
   Bypass any power regulators like surge protectors, UPS (uninterruptible power supply), power splitters.
5. Power on the computer.

If the power cable and the wall outlet are working correctly and the computer is not able to turn on, go to the next step.

Reseat the AC adapter by following these steps:

1. Unplug the AC adapter from the wall outlet for 15 seconds.
2. Unplug the AC adapter from the computer.
3. Plug the AC adapter to a known-good wall outlet. Bypass any power regulators like surge protectors, UPS (uninterruptible power supply), power splitters.
4. Plug the AC adapter to the computer.
5. Check the LED indicator on the AC adapter.

If the AC adapter LED indicator is on, go to the next step. If the AC adapter LED indicator is off or turns off when it is connected to the computer, contact Dell Technical Support for repair options.

Verify that the voltage selection turn on the power supply unit is set to the correct voltage based on your current location. The power supply unit (PSU) of certain Dell desktops allow you to change the voltage from 110 V to 220 V depending on your current location.

For example, the standard voltage that is supported in the United States is 110 V and 230 V to 240 V in the United Kingdom. Ensure that the toggle turn on the power supply unit (PSU) is set to either 110 V or 220 V based on your current location.

If this did not resolve the issue or if there is no voltage selector toggle switch, go to the next step.

Dell Inspiron, XPS, OptiPlex, Precision, and Vostro desktop computers include a power supply with an integrated self-test (BIST) feature that helps diagnose the health of the power supply unit. The LED indicator on the PSU helps identify if the power issue is caused by the power supply unit.

How to run the self-test using the button on the PSU

1. Turn off the computer.
2. Press the BIST button on the computer and check whether the LED lights up.
3. The light should be solid on not flickering or flashing, and the power supply fan should also turn on to speed. If the fan is not spinning up properly this should be considered a BIST failure even if the LED lights up.
4. If the integrated self-test LED turns on, then the power supply unit can deliver power to the system board.
5. If the BIST LED does not light up, then the power supply is not able to deliver power to the system board and could be caused by any component that is connected to the power supply or the power supply itself. The next step would be to isolate the source of the power failure by disconnecting parts from the PSU, see the Dell knowledge base article Resolve No Power, No POST, No Boot or No Video issues with your Dell Computer.

How to run the self-test without the button on the PSU

1. Turn off the computer.
2. Disconnect the power cable from the PSU, and wait for 15 seconds.
3. After 15 seconds, connect the power cable back to the PSU.
4. The LED light should stay on for 3 seconds and then turn off.
5. If the integrated self-test LED turns on, then the power supply unit can deliver power to the system board.
6. If the BIST LED does not light up, then the power supply is not able to deliver power to the system board and could be caused by any component that is connected to the power supply or the power supply itself. The next step would be to isolate the source of the power failure by disconnecting parts from the PSU, see the Dell knowledge base article Resolve No Power, No POST, No Boot or No Video issues with your Dell Computer.

If this did not resolve the issue, contact Dell Technical Support for repair options.