Laptop automatically powers on when plugged (no post)

I have had several broken laptops that had the following issue: as soon as the charger is plugged into the laptop, the laptop will automatically turn on (without pressing the power button). The laptop wouldn't fully boot. In one case the laptop would just keep restarting, on another laptop it would just turn the lights on without booting. A laptop should turn on only when the power button is pressed. What makes the power bypass the power button and turn on?

I am trying to understand why a laptop would automatically turn on when plugged with power supply without pressing the power button. Any thoughts about this issue?
Reply to netspiderz
10 answers Last reply
More about laptop automatically powers plugged post
  1. I would think this is a BIOS or motherboard design fault.

    basically what happens, when you plug it in, there's some circuits that begin functioning like battery charger, some LEDs etc.

    it's similar like if you take a WD external HDD and just plug it in, it will power on for a few seconds then detect that there's no data connection and shut off. I don't know, maybe they've solved that issue by now, not that it's a big problem.

    So, in case with a laptop, I'd think it's a similar issue, it detects AC power, essentially the motherboard turns on at that point. So maybe in your case the motherboard is faulty or BIOS is not configured properly and it does a false start.

    here's a few options to check out:
    - update BIOS if possible
    - do the laptops have functioning battery?
    - how about CMOS/BIOS battery?

    basically, pull out the laptop battery let the laptop sit for a bit then plug in, do you get the same behavior? also, unplug the battery, unplug ac, hold the power on button for 10 seconds, then plug in DC and check what happens. Does the BIOS time reset? Does it reset when you just take out the laptop battery?

    Basically there's 3 power sources for the motherboard ac adapter, laptop battery and CMOS battery (I think newer laptops are beginning to omit this one). If either of them goes bad or is malfunctioning you might experience strange behavior.

    Also, if you have a possibility try a different charger and different battery (if you have same in household or borrow somewhere)

    So experiment a little bit, let us know what you find.

    In the end it might be just a motherboard hardware fault in relation to power adapter that there's nothing you can do about it.
    Reply to AntiZig
  2. AntiZig thanks for your suggestions, I will definitely try those out and I will let you know.
    Reply to netspiderz
  3. i have the same problem, but my problem started when i spoil alcohol on my laptop, it stopped working for 3 months then it start working but it turns on automaticlly when it connected to AC power and it also turn off automaticly sometimes and sometimes it work noramlly, have you fixed yours? if so how?
    Reply to abood512
  4. i fixed it i just had to change the small battery inside.
    Reply to abood512
  5. AntiZig said:
    I would think this is a BIOS or motherboard design fault.

    basically what happens, when you plug it in, there's some circuits that begin functioning like battery charger, some LEDs etc.

    it's similar like if you take a WD external HDD and just plug it in, it will power on for a few seconds then detect that there's no data connection and shut off. I don't know, maybe they've solved that issue by now, not that it's a big problem.

    So, in case with a laptop, I'd think it's a similar issue, it detects AC power, essentially the motherboard turns on at that point. So maybe in your case the motherboard is faulty or BIOS is not configured properly and it does a false start.

    here's a few options to check out:
    - update BIOS if possible
    - do the laptops have functioning battery?
    - how about CMOS/BIOS battery?

    basically, pull out the laptop battery let the laptop sit for a bit then plug in, do you get the same behavior? also, unplug the battery, unplug ac, hold the power on button for 10 seconds, then plug in DC and check what happens. Does the BIOS time reset? Does it reset when you just take out the laptop battery?

    Basically there's 3 power sources for the motherboard ac adapter, laptop battery and CMOS battery (I think newer laptops are beginning to omit this one). If either of them goes bad or is malfunctioning you might experience strange behavior.

    Also, if you have a possibility try a different charger and different battery (if you have same in household or borrow somewhere)

    So experiment a little bit, let us know what you find.

    In the end it might be just a motherboard hardware fault in relation to power adapter that there's nothing you can do about it.

    Reply to sumanhardware
  6. I have same problems , but one case addition that my laptop battery is very poor , so can i used SMPS insted of used laptop batter to sloved the issue.
    Reply to sumanhardware
  7. I too have the similar problem on my HP Compaq 6710b..
    The laptop powers on when i force plug in the charger and the laptop works fine after that..
    But the laptop never turns on when i try to power on my pushing the power button!!
    Very annoying.. Does anyone know the reason why?? Is the same BIOS the reason here too with me??
    Reply to Danno911
  8. Guys, it is simple, go to BIOS and under power management you will see an option "Wake on AC" or "Power on AC," mentioned. Just disable or unclick this option and you are done. BIOS settings would be different in different brands, but the steps are same,. You just need to disable or unclick the box next to this, so that the laptop does not power on when a adapter/charger is plugged in.

    Thanks,
    edited by ffg7
    Reply to resetsystems1
  9. resetsystems1 said:
    Guys, it is simple, go to BIOS and under power management you will see an option "Wake on AC" or "Power on AC," mentioned. Just disable or unclick this option and you are done. BIOS settings would be different in different brands, but the steps are same,. You just need to disable or unclick the box next to this, so that the laptop does not power on when a adapter/charger is plugged in.

    Thanks,
    edited by ffg7


    it happens even with "Power on AC" option unchecked on my DELL Latitude E6410 ; My guess is either Operating System is taking over BIOS (I'm using windows 10); {I don't bother to go find windows power on settings and then test this hypothesis} :p OR Otherwise it's some BIOS software/hardware fault
    Plus my laptop battery condition is also poor AND based on other posts here I suspect it could be the battery issue; Might replacing battery with a new one help
    Reply to MaddyTomsguide
  10. MaddyTomsguide said:
    resetsystems1 said:
    Guys, it is simple, go to BIOS and under power management you will see an option "Wake on AC" or "Power on AC," mentioned. Just disable or unclick this option and you are done. BIOS settings would be different in different brands, but the steps are same,. You just need to disable or unclick the box next to this, so that the laptop does not power on when a adapter/charger is plugged in.

    Thanks,
    edited by ffg7


    it happens even with "Power on AC" option unchecked on my DELL Latitude E6410 ; My guess is either Operating System is taking over BIOS (I'm using windows 10); {I don't bother to go find windows power on settings and then test this hypothesis} :p OR Otherwise it's some BIOS software/hardware fault
    Plus my laptop battery condition is also poor AND based on other posts here I suspect it could be the battery issue; Might replacing battery with a new one help


    I have the same problem white my DELL Latitude E6410 Bios is put right but same problem.
    Reply to Emil_14
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