Table of contents: 1. Computer turns on by itself because of the hardware problems 2. Computer turns on by itself because of software problems - BIOS - WINDOWS
Computer turns on by itself because of the hardware problems
The most common problem which may make your PC to turn on by itself is the power button malfunction. Most often, the power button is located on the front panel of the system unit, and it is enough to press it to power the PC components and start the system boot. But the wear of the power button or the oxidation of its contacts may lead to a spontaneous PC start.
It is quite easy to make sure that your computer turns on by itself due to a faulty power button. It is necessary to disconnect the button from the motherboard, most often it is connected by two contacts that go to the pins with the PWR (Power) marking on the board. Disconnect the power button and observe computer behavior in the “off” state. If it no longer turns on by itself, you can be sure that the button is malfunctioning. A defective button should be replaced. Or you can just clean the contacts of the current one if there are signs of oxidation on them.
Another hardware problem that may make your computer to turn on by itself without you even touching the power button is the power supply. Some PSU models may turn the computer on when a voltage comes, if their power button is set to “On”. To determine if such an option is available in your computer, you need to read the motherboard manual. Most often, this problem is related to BIOS settings, and below we will tell you what you can do on this matter.
Computer turns on by itself because of software problems
Your computer may turn on by itself due to BIOS and Windows settings, and below we will discuss each one of them separately.
BIOS
BIOS has a number of settings that allow you to turn your computer on in one way or another without pressing the power button, even if it is not in sleeping or hibernation mode. Depending on the BIOS version, names of the settings discussed below may vary, but they are available in almost all basic input/output systems.
The following BIOS settings may make your computer turn on spontaneously:
- Power On By Mouse or Power On By Keyboard. These BIOS options are responsible for the ability to turn the computer on with mouse and keyboard. For your PC not to turn on by itself because of external manipulators these options must be switched to the Disable mode;
- Modem Ring Resume, Wake On LAN. Options that allow you to turn your computer on by sending the appropriate command from another computer – from the outside (or inside the local network). These options should also be disabled to prevent your computer from turning on spontaneously. It is important to note that if, due to these settings, your computer turns on by itself, it’s far from the fact that some intruders are trying to connect to your computer from outside. Quite often, network or motherboard errors result in the transmission of turn on command;
- RTC Alarm Resume. The “alarm clock” option in BIOS. If desired you can configure this option in such a way that your computer will turn on at a specific schedule. This is useful, for example, if the PC is in the office, and you need to access it remotely at a certain time. Often, virus applications configure the spontaneous computer activation through the RTC Alarm Resume option in BIOS. Make sure it is off;
- Power-ON After Fail. This option we have already mentioned above. It allows you to turn on your computer when a certain voltage is supplied to the system unit. It should be noted that this setting does not work with all PSUs.
- ACPI Suspend Type. This setting is responsible for the “depth of sleep” of the computer. If it is set to “S1 (POS)”, then the computer goes into sleep or hibernation mode in a standard way, that is, coolers continue to work and the computer, in general, gives signs of life. However, if this option is set to “S3 (STR)”, then the computer looks disabled, even if in fact it “sleeps”. In this case, you may think that you are turning your PC off while in fact you are just putting it to “sleep”. This happens for example, if to turn your PC off you are using not the corresponding Windows command, but the Power button on the system unit.
If you cannot find one or more of those BIOS settings that might affect the spontaneous PC turn on, you can simply reset the base system settings to the “default” option. This can be done (most often) by pressing the F9 key in BIOS environment. You can also reset BIOS to its default values if you remove the battery from the motherboard for 20-30 minutes.
WINDOWS
Some Windows OS settings may also lead to the spontaneous power-up. First, make sure that the power button turns off the computer, and does not put it to sleep or hibernate. To do this, go to the “Control Panel”, select “Power Options”.
In the left part of the window select the “Choose what the power buttons do” section and set the computer to shutdown when the power button is pressed.
Another parameter that needs to be configured in Windows so that the computer does not turn on by itself is the “Wake Timer”.
Go to the settings of the selected power scheme and in additional power settings make sure that the wake timers are disabled.
After applying all the above tips, the problem when your computer turns on spontaneously should be resolved. If this does not happen and the computer is still turning on by itself, use the shutdown button on the system unit to avoid this.