No power or computer does not turn on
No power or computer does not turn on.
No power from the computer can be caused by any of the below possibilities.
- Connections not connected properly.
- Third-party hardware.
- Bad power cable.
- Incorrect power supply.
- Bad battery.
- Bad power supply, power button, or power board or inverter.
Notice: If the computer is turning on but is not posting (beeping) or giving any picture on the display, see POST troubleshooting. This page also does not cover 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 in the computer or 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.
Connections not connected properly
Verify that the power connection is connected properly to the wall and the back of the computer. If the connections appear to be connected properly, disconnect and reconnection both ends of the power cord to make sure the cable is not loose.
If you have a power strip (surge protector) or switch used to turn everything on at once, temporarily disconnect the computer from that switch and connect that cable directly to the wall. This will help verify that the strip or switch is not bad.
Verify that the outlet works by connecting a different component to that switch.
If additional hardware has been recently added to the computer it is recommend that you temporarily disconnect that device or devices from the computer to verify they are not preventing your computer from turning on.
Note: If the computer was working fine before you added the new hardware, removing the third-party hardware did not resolve the issue, and the computer is not beeping but isturning on, see the POST troubleshooting steps.
Bad Power cable
Verify that the cable supplying 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 your own computer or if the computer has never turned on since you purchased it, it is possible you are using a power supply that does not supply enough power or the incorrect power supply. Verify your power supply meets the requirements of your motherboard and processor.
If your computer is a laptop or portable computer that utilizes a battery for mobility it is possible that the battery 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 when the battery is connected and when the power cable or charger cable is connected, try removing the battery and seeing if the computer can power on with only the power cable connected. If no power is still received, skip to the final section.
Bad Power Supply, power button, or 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 most likely that the power supply has failed. If you do not plan on replacing the power supply yourself or if you have a portable computer, we recommend having the computer serviced by your computer manufacturer or a local computer repair shop.
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.
- First open the computer and verify the power connections. You may also wish to consider 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.
- Replace the power supply with a new power supply.
- Replace the motherboard.
- Computer powers on and then immediately turns off.
- See the boot definition for further information and related related links.