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  • #2141740

    laptop won’t start after cmos battery reset.

    by kareenkka ·


    Hi i have a dell inspiron 5559, my laptop was working fine until i took the cmos battery and replaced it again. I had an issue with my AC charger being unrecognized so i wanted to turn off the warning, but i had an administrator password set, which i dont know, that’s why i decided to reset the cmos to remove the password.
    But know when i try to turn on the laptop nothing starts at all except the fans keep running very fast, completely black screen (dosen’t turn on), no keyboard lights, and the Battery indicator goes white and orange. Could this be that the bios is corrupted even though i reset it, or the whole motherboard is dead? If it’s bios failure how can i reinstall it? please help, i need an advice.

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    • #2419942
      Avatar photo

      As to the BIOS. I’ve never found a corrupt BIOS in decades.

      by rproffitt ·

      In reply to laptop won’t start after cmos battery reset.

      I have seen many motherboard failures but sometimes an owner knows more than they reveal so if you know more, use that knowledge to replace what you suspect.

      -> I wonder what lead you to reset the bios settings like this. We know the admin password isn’t reset with a battery removal. That hasn’t worked for about two decades.

      But the flashing has been discussed many times before. Read and try the ideas at

    • #2420001

      I don’t know that particular NB but

      by the master2 ·

      In reply to laptop won’t start after cmos battery reset.

      Just removing the BIOS Battery isn’t going to clear the Security Password this requires shorting out something like Pins or Pads on the M’Board while the unit is unplugged and the battery removed.

      Generally you do not remove the CMOS Battery but as I say it depends on the Make and Model of the M’Board. Some of the old IBM’s could not have the Security Password cleared if you did not know the Password you had to simply open that section of the BIOS type in the old Password and leave the New Password Space Blank and that was the only way to remove it short of replacing the M’Board.

      As for what to do now you need to remove the Charger, the Battery and then remove the CMOS Battery from the M’Board and then hold the Power On Button down for at least 20 seconds. If that doesn’t work it’s a New M’Board time unfortantly.

      • #2420000
        Avatar photo

        This model Dell won’t allow that sort of reset.

        by rproffitt ·

        In reply to I don’t know that particular NB but

        Here’s how you get around the Admin password:

        “The system owner needs to contact Dell with Service Tag / Proof of Ownership and Dell will generate a Master Code.”

    • #2419998

      Laptop is working fine

      by kareenkka ·

      In reply to laptop won’t start after cmos battery reset.

      I removed the cmos battery for about 10 hours and put it back again, now my pc is working fine but the admin password is still there. I will try to contact dell support for password.

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