Power switch on the power strip surge protector or ups if you re using any of them check for disconnected computer power cable connections.
Power supply switch won t turn off.
Mine won t turn off unless i cut power to the powersupply by either turning off the power strip or pulling the plug from the back.
Pull power cord from wall.
Power on and test it.
Chances are your computer wouldn t power on at all if this switch is wrong but an incorrect power supply voltage might also cause your computer to turn off by itself.
Capacitors vary widely in quality with some brands likely to fail in about 3 years coincidentally those power supplies tend to have warranties of 3 years or less while other brands will almost certainly last at least 5 10 years 5 year warranty is a sign of this.
Try this called a hard power reset.
Flip the switch at the rear of the psu and listen for the internal fan.
Then push power button with line ac cord not connected.
1 force restart hold down the power button for at least 12 seconds until the switch console turns off.
Power cord back now.
O should be down locate the 20 4p 24 pin connector.
First you want to turn the power switch at the rear of the power supply to the off position.
It s better to flip the switch because there will be less wear on the capacitors in the circuitry of the 5vstandby supply.
Bend the paperclip and insert one end into the green pin ps on and the other into any of the black pins ground.
Once the switch has been completely powered off press the power button again to turn it back on.
Verify that the power supply voltage switch is set correctly.
See fans spin for 1 second is very very common.
There is no master power switch on this power supply as someone.
See it will turn off.
All i can do then is keep the power button pressed for a few seconds and finally the power supply stops or press the reset button to start the computer again or click the power switch of the power supply in the back of the computer tower off and on when clicked on again the computer keeps turned off.
A loose or unplugged power cable is one of the top reasons why a computer won t turn on.
Wait 15minutes this further discharges huge capacitors inside.
If the input voltage for the power supply does not match the correct setting for your country your computer might not stay powered on.
To help protect a computer from being improperly turned off when it s running the power button will not turn off a computer.