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BIOS password won't clear

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by daz'n'ash

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I ave an old 486 computer (yes I know it is old, it is for kids) and the bios is locked with a password. I have removed the jumper on the mobo to clear the cmos, it didn't work. Tried leaving the jumper off for about 15 minutes, still not clearingthe cmos. Have unplugged it from the power completly for 48 hours, still the cmos won't clear. I need to be able to enter bios setup to get it to detect the 3? floppy drive so I can get a command prompt.

Any other way to remove the password?

17 replies

by maxwell edison

The jumper to clear the BIOS usually works. Make sure you're using the correct jumper. If that still won't work, you may have to flash the BIOS. But, of course, to do that, you'll have to boot from the floppy (which you can't). The boot order set inthe BIOS is, most likely, C-Drive first, A-Drive second. Unplug the ribbon cable from your hard drive. That will force the computer to boot from the floppy.

by daz'n'ash

Ecellent idea. I didn't think of doing it that way. Thank you for your response Maxwell.

by hinrgman

Try removing the bios battery. The jumper was probably shorted out to prevent someone from doing what you tried to do

by daz'n'ash

It is the type of BIOS battery that is fixed to the mobo, unfortunately can't be removed.

by randalbin

On some motherboards simply removing the jumper is not enough. In some cases there are three pins and you must remove the jumper from 1-2 and connect 2-3 for a few seconds and then replace the jumper on 1-2.

If this doesnt work or isn't applicable to your board, then you will have to disconnect the power and remove the cmos battery to clear the password. In some cases you may have to leave the battery out for an hour or more.

by daz'n'ash

Thanks for your response. I already thought of doing this, tried the jumper in various places to be sure, also the bios battery is fixed to the mobo, so unfortunately cannot be removed. I did say the mobo was old lol

by fenaikh

Hi
1- Use the motherboard manual to locate the correct Locattion of the jumber or jumbers and then folow the instruction on how to set them or changing the position of a jumper that will clear the BIOS settings.

2- Unplug the power source from the machine (must do first before clearing CMOS) and pull out the battery that maintains the BIOS settings in RAM then set jumbers to clear CMOS.

3- plug the machine then reboot.

4- Unplug ( must do again) then reset the jumber to normal then plug and reboot.

Other posibble sloutions:

there are free utilites check them in the inernet when i find them i will post the address or URL. such as the CLRCMOS util from Award.

1- A utility to crack BIOS password.
2- A utility to clear CMOS.
3- A debug script to clear the BIOS password and allow access to CMOS.
4- A backdoor passwords if your BIOS has one.
5- A switch on the motherboard which is used for clearing CMOS and passwords.
6- A rest button on the motherboard which is used for clearing CMOS and passwords.
(new motherboards)

more info:
http://www.wimsbios.com/

How do I clear CMOS / NVRAM using the debug command?
http://www.techtips4u.com/kb/sw/SW00025.htm

Good luck

Mohamed

***Very Important NOTE *********
After you copy the URL a space or a %20 maybe gets inserted in the URL when you paste it into your browser. Delete any spaces or such characters from the URL for the page to be loaded.
***Very Important NOTE *********

Mohamed

by daz'n'ash

Again, a very intelligent response to my question. All very valid ideas, but have tried the jumpers without success. I pulled the power plug for over 48 hours, still didn't clear the cmos.

by jesus.diaz

This is tricky and may whack the little 486 put I have successfully zapped a bios to clear it. I leave up to you to decide how build up enough Electro Static to zap the bios. You can always get a new bios from Mr. Bios if this one is not soldered in.

Just some crazy ideas that might work. :)

by opatzg9

If that doesn't work you could always buy an old pentium 90 from a recycle shop for around $25 and give that to the kids. Just a thought before you spend way to much time and anxiety on a 486. otherwise I have 2 486's I'm not using.

by tourist tech

every one seems to say the same thing but as well as unplugging the battery and moving the jumper it is worth disconnecting the motherboard connector from the power supply as capacitors within the power supply can hold the supply for the bios

by daz'n'ash

Good idea, but unfortunately, I have tried that without success. Thank you for taking the time to reply.

by exp

Have a look at some of your answers are quite good and on the right track. I wouldn't try to Zip the BIOS chip with static. One thing people forgot is that the BIOS setup info does not reside in the BIOS chip but a peripheral chip. Have a look at your board if you have a rechargable battery soldered or a Dallas 1287 etc on the board and you havn't got the manual I think you may as well go and buy a 2nd hand board. If your board has a CR3025 or similar battery (or even a battery plug on the board) then there is a chance you can clear the CMOS. Follow the step below.
1/ power off the PC unplug the power cable.
2/ disconnect any batteries that is on board.
3/ get a small wire (test lead will be the best thing) about 20cm long with bare metal(trim the insulation) at least 1cm on both ends. connect one end to earth (any bare metal on the PC will do).
4/ short the other end of the wire on to the pins of all the chipset on board, don't go too fast and don't worry you won't shorted any chips I have done this many times. I will only short all the big chips wouldn't worry about any TTL or glue logic chips.

good luck

by daz'n'ash

Thanks for the ideas, but manual for the mobos cannot be located anywhere we have searched as yet.

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