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Disabling Power-on Password

By jrbralley ·
How do I disable the power-on password of a 486-based Panasonic Laptop? There are no apparent jumpers and the battery is soldered in. At present, two laptops are useless because I do not know the password.

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Disabling Power-on Password

by mpdcsup In reply to Disabling Power-on Passwo ...

If you can get to the two leads on the battery, try shorting it momentarily (less than 1 second). It will drain the battery slightly, but not completely (unless it's already low).

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Disabling Power-on Password

by Shanghai Sam In reply to Disabling Power-on Passwo ...

This seems a bit risky at this point. I'll use only as a final fresort. Thanks. JRB

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Disabling Power-on Password

by Diamond Dan In reply to Disabling Power-on Passwo ...

Hi,

Another idea: depending on the model, some older 486's still had a removable bios chip. You could try pulling the chip and letting it sit for a few hours to drain the capacitance and allow it to reset that way. If you can't remove the batteryfrom the chip, remove the chip from the battery!

BTW, the previous post will probably not work for two reasons:
1) shorting out the battery will not drain the onboard capacitor, which will continue to supply current to the chip
2) the brief one second shortout is not long enough to reset bios chip data.

Good Luck,
dan

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Disabling Power-on Password

by Diamond Dan In reply to Disabling Power-on Passwo ...

and one more thing why shorting out the battery is a bad idea:

you could damage the battery or cause a premature death to the battery, and since it is onboard it could be difficult to replace. Once the battery is shot you will have to renew BIOS data every time you reboot, and I don't think that's what you want to do.

Trust me, this happened to me once, and I had to reset my date, time, hard drive specs, etc. every time I rebooted the machine. BAD IDEA!

-dan

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Disabling Power-on Password

by Shanghai Sam In reply to Disabling Power-on Passwo ...

Good advice as I don't want to deep-six a soldered-in battery. Thanks. JRB

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Disabling Power-on Password

by freetech In reply to Disabling Power-on Passwo ...

put the regular laptop battery in and turn on machine and set for "always on" in power management (video properties).
just leave the machine on until the machine drains its batteries and the bios (should) reset itself. if the machine doesn't go into power-saving mode, this should only take a few hours. note, this is hard on the battery life and may shorten it some.

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Disabling Power-on Password

by Shanghai Sam In reply to Disabling Power-on Passwo ...

Running the regular battery down will not deplete the CMOS battery. But thanks for comment. JRB

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Disabling Power-on Password

by jwilczyn In reply to Disabling Power-on Passwo ...

You can clear CMOS(e.g. password) by shorting pins. To find them, you must look on the board for something as JBAT, Clear Data/Keep Data, CMOS RAM, etc. When you located them - short them, while the system is off.
Removing a battery may help in resetting same data but it's usually for date and time only.
Check:
http://www.computerhope.com/issues/ch000235.htm
http://www.wimsbios.com/
http://www.computerhope.com/network/bios.htm

Good luck

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Disabling Power-on Password

by Shanghai Sam In reply to Disabling Power-on Passwo ...

This sounds like the solution I need. I will try this option. At present the laptops are not accessible to me. Thanks. jrbralley

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Disabling Power-on Password

by jrbralley In reply to Disabling Power-on Passwo ...

This question was closed by the author

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