No power or computer does not turn on

Note: This page relates primarily to desktop computers and the most common causes for the computer to not have power or turn on. More specific troubleshooting steps for a laptop computer can be found on our page for a laptop computer that is not turning on.

If you are uncertain if the computer is turning on or not, this can be checked by locating any fans inside the computer or fans that are visible from the outside of the computer. If these fans are spinning, the computer is receiving power and this document may not apply to your issue.

Note: If the computer is turning on but is not posting (beeping) or showing any picture on the display, see POST troubleshooting.

Power cord not connected properly

Computer power cordVerify that the power cord is connected properly to the wall and the back of the computer. If it appears to be connected properly, disconnect and reconnect both ends of the power cord to make sure the cable is not loose.

If you have a power strip (surge protector) that turns everything off/on at once, disconnect the computer power from it and connect it to the wall to verify that the strip is not bad.

Verify that the outlet works by connecting another electrical device to that switch.

Third-party hardware

If any hardware has been recently added to the computer, it is recommended that you temporarily disconnect or remove it to ensure that it's not the cause of your issue.

Note: If the computer was working fine before you added the new hardware, and the computer is not beeping but is turning on, see the POST troubleshooting steps.

Bad power cable

Verify that the cable supplying power to your computer is not bad or damaged by using another power cable. If you have a standard CRT monitor, this cable can be used in place of the computer power cable.

If you have a portable computer or laptop, when the cables are plugged into the laptop, you should see a power light or battery charge light. If this light is seen, this is a good indication that the power cable is good.

Incorrect power supply

If you are building a computer or it has never been turned on it may have a defective power supply that is not supplying enough power. Verify your power supply meets the requirements of your motherboard, processor, and video card.

Bad battery

If your computer is a laptop or portable computer that utilizes a battery for mobility, it may be causing your issue.

  • If your computer powers on when the cable is connected to the portable computer, but not when it is disconnected, we recommend you purchase a new battery.
  • If your computer does not power on with the battery and power cable connected, try removing the battery (if possible) and see if the computer can turn on with only the power cable connected. If no power is still received, skip to the final section.

Bad power supply, power button, power board, or inverter

If, after following the above sections, your computer still receives no power, it is likely that a hardware component in the computer has failed. It is possible the power supply has failed. If you have a laptop or do not want to replace the power supply yourself, we suggest taking the computer to a repair center.

If you have a desktop computer and plan on trying to repair the computer yourself, we recommend you replace the components in your computer in the below order.

  1. First open the computer and verify the power connections. We recommend disconnecting the main power cable and reconnecting the power cable to make sure it has not become loose. Also, verify the power button cable is correctly connected to the motherboard.
  2. Replace the power supply with a new power supply.
  3. Replace the motherboard.

Additional information