Reset BIOS - How to ??

I have to agree with MisterX,

I came across a Dell bios that couldn't remove the password by conventional means, this was usually found on dell laptops.

The tool you might need is just a metal paper clip to join two legs together to short it (insulate the part you hold, then again 12Vs does just tickle a bit but dropping the paperclip may cause more problems!) but without knowing what chip it's using you'll probably need to find your own schematics for it, since I can't recommend just testing two pairs of legs out without damaging the chip.


Cheers,


MC

Comment/Reply (w/o sign-up)

Reseting the bios on computers
Reset BIOS

(G)Author Name - e.G. John, Mike,

You're the one being dumb.  many newer models of computers don't rely on the battery to preserve the CMOS memory, as a protection method.  Dell is a good example with PCs.  You have to remove the battery, change a jumper, put the battery back in, wait a bit, reverse the steps, etc to wipe it out.  There ae other methods too.  Apparently you are the one not keeping up to date with technology.  iGuest-edfrgwerg had it right.

And you call yourself a PC doctor.  lame.

-reply by MisterX

 

Comment/Reply (w/o sign-up)

reset bios on a laptop
Reset BIOS

Taking out the battery will not set the BIOS? I don't know what school you went to, but taking out the battery which causes the CMOS chip to lose power and consequently resets itself. And what's all that other stuff you are babbling about? He just wants to know what time it is not how to fix the clock, unless you are trying to impress everyone. You probably making half of it up as you go along...So go back to your Geek chair, let te men take care of this one..Take the battery out, wait five minutes, put it back...That's it.

The PC Doctor 

Comment/Reply (w/o sign-up)

The BIOS on my computer can be reset by pressing a button on the motherboard 'Reset CMOS', but this method is only available on new motherboards with onboard diagnostic features.

You could also reset the CMOS / BIOS by removing the CMOS battery from the motherboard for 15-30 minutes, or by triggering the CMOS jumper on the motherboard.

For more info, a good source of information on resetting the BIOS is:
http://www.askvg.com/how-to-reset-remove-b...-cmos-password/

Comment/Reply (w/o sign-up)

None of these will work. !bios / cmospwd / spotmau etc. Don't yet know about these modern bioses and so just return 100% gibberish; their blanking functions target the wrong addresses also.

The password info is held inside nonvolatile memory which either does not require constant power to retain the data, or else is backed up by an unidentified smt capacitor somewhere on the board (capacitor's my conjecture)

The memory used generally resides within the main peripheral controller chip and is not addressable by the 'normal' address bus used by general programs.

So, removing the cmos battery accomplishes nothing.

Reflashing the bios also does nothing more than replace the bioses running code, it does not replace the password memory within the controller chip.

One would need to identify whatever pins are used on the controller chip to access the memory, attach some form of piggyback hardware, and 'milk' the password data out of it. This would entail knowing precisely how to address the memory within the chip (pulse timings) and also exactly which addresses to read.

Then, one would need to know exactly what algorithm the bios was using to hash down from a readable password to whatever encrypted form is held in the controller chip. Then you could -possibly- write code to determine ascii strings which resulted in the same hash.

No doubt the '0000' or equivalent hash (resulting from a simple hardware clear of the password memory) has been foreseen and coded against.

Software and hardware designs to break these newer bioses will no doubt come about eventually but there's a waiting period whilst the geeks fiddle around, and this time the budding bios password cracker will need a soldering iron, pretty good electronics construction skills, and a good quality oscilloscope.

Look deeper into the subject of 'Trusted Computing' and you'll see all this is the least of the worries about the future of smalltime computer repair. Soon enough, if you're not Dell or Siemens, you'll have no hope doing anything. Personally, I'm going back to gardening :)

-reply by edfrgwerg

Comment/Reply (w/o sign-up)