This is a very rare case that some users experience that the computer turns on automatically when plugged in .The computer turns on automatically when plugged in without pressing the Startup switch located in the cabinet.This type of problem can prove to be very disastrous for your computer as it can create severe problems for the hardware especially the Motherboard causing burnout of motherboard . Also there are chances of losing valuable data from the hard disk so it is highly recommended that you should backup your important data when you start experiencing this kind of problem.When you plug in your computer you will experience that all the cabinet and PSU (Power supply) fans are running and motherboard light is also on but there is no display on the Monitor until you actually press the Startup switch on the cabinet.Also during the shutdown process you will find that after shutdown process still all the cabinet and Power supply fans are running and motherboard light is still on.This problem must be resolved before it could cause some serious damage to your hardware parts.This problem can arise due to various reasons but most common reasons are given below with proper solution.
Reasons for This Problem ( Computer turns on automatically when plugged in ):
Faulty PSU(Power Supply) – A faulty PSU can be the culprit of this problem .Generally this kind of problem arises due to a faulty Power supply.Power supply causes this kind of problem when its wires are getting shorted somewhere and thus causing an automatic startup after plugging in. You can test your Power supply by performing a paper clip test of Power supply.
Faulty Motherboard – A faulty motherboard can also cause this problem by shorting the 24 pin power supply wires . So make sure that all the power cables are properly placed in the motherboard so that it should not short the power supply.
Bios Problem – Check all the bios setting of the motherboard and check the power options located in the bios option and make sure that the power option in the bios is set to stay off in all the conditions.
Faulty Cabinet Startup Switch – Shorting of wires at the Cabinet startup switch can also cause this kind of problem.
* If you experience computer turns on automatically when plugged in with a beep sound than it can be a problem of a faulty RAM or hardisk .
Fix Computer turns on automatically when plugged in
- Check your power supply by performing a paper clip test because if a power supply turns on after plugging in without actually shorting the wires then it is a faulty power supply so replace it as soon as possible. You can perform a paper clip test by seeing the below video demonstrating how to perform a paperclip test on a Power supply.
- Check all the wiring’s near the start up switch and make sure that they are not shorted .
- Also check the Power settings in the bios and make sure that the power option in bios is set to stay off in all the conditions.
- If power supply , start up switch and bios are all ok then it is all due to a faulty motherboard .
* Also make sure to check your RAM and hard disk Separately