BIOS password prompt. Owner did not set a BIOS password? How to clear/bypass password lock?

This Vaio notebook prompts for a BIOS password at power-on.  Also will not allow BIOS config without password.  The owner did not set a password.  
Is there a way to bypass this prompt?  I have disassembled the top of the notebook and I do not see any mini-dipswitches (maybe on the underside of the mainboard?) ..
There is a 2.4V battery-pak.  Disconnecting this seems to set BIOS defaults however there is still a BIOS prompt for a password.  Any ideas?

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Gary CaseConnect With a Mentor RetiredCommented:
As nobus noted, this system almost certainly uses a security chip.

The most well-known feature of the security chip -- and one that really frustrate legitimate owners who don't realize how secure this chip is and manage to forget their password --- is that it stores any BIOS passwords you set in a VERY secure manner.

You can set a password to access your PC -- and it will be stored in the chip.   BUT, if you do so, be sure you DO NOT FORGET it.   With the security chip, if you forget your password, there is NO WAY to reset it.   It will require a motherboard replacement !!   Well ... not quite => you can, with the right SMD soldering/desoldering skills replace the security chip.   A replacement security chip for the Sony is available here:

Note that the security chips are, from a security perspective, a very good thing.   But there are been frequent postings from folks who forgot their passwords hoping to find a way to reset them.  Answer is:  you can't :)

One other note:   It's unfortunately not uncommon for folks to accidentally set a password without realizing it.   I always recommend that if you have a security-chip enabled laptop you SHOULD set a password you won't forget ... even if it's something simple like "password" ... so that you can't ever do it by accident (since you'll then be prompted for the "old" password before you can change it).
DarkerConnect With a Mentor Commented:
Depending on the version of PhoenixBIOS the laptop has you could try:

Another thing to try would be down/upgrading the BIOS to a different version, many times this reset the options and may reset the password.
PCLANTECHSAuthor Commented:
Thank you for the info.  An excellent link...  For this job, however, I will need to pull the eeprom chip as I cannot get to DOS or access a boot device without the password.  The documentation for CMOSPWD indicates the following eeprom for Sony: pcg-fx950: eeprom 93c46.
I will need to confirm the same chip is in the PCG-V505EX and then pull the data sheet for the chip.  What a pain...

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Ugh, that is a pain
nobusConnect With a Mentor Commented:
in modern laptops, bios passwords cannot be recovered; you need to contact the Viao people, and show proof of ownership.
it is not kept in the bios chip, but in a security chip
Garycase, verging on OT here, but I have noticed a number of threads where the asker claims that no BIOS (or HD!) password has ever been set, but suddenly a pw request pops up at startup. Are you aware of any sort of circumstances that could trigger the setting of a password in BIOS without user intervention? Power glitches, misbehaving software, anything?
Gary CaseRetiredCommented:
rid =>  I've noticed the same thing ... and it's very strange.  Also very disruptive, given the exceptionally good security of a security-chip enabled system.   The security chips are supposed to be very immune to spurious signals ... and the software protocol to write the passwords is very secure.   But it does seem strange that several "accidental" passwords seem to showing up in EE threads.   It would be interesting to know if all of these are using the same security chip ... might indicate a design flaw in that specific chip.  But it could also simply be a case of inadvertent passwords being set while in the BIOS ... another good reason to be sure you set a password on a security-chip enabled system (but of course be sure it's one you will NOT forget !!).
have you already tried to unpatch the 2.4V battery and startup the pc without his own battery, but with the power supply only?
Maybe could help you as helped me in some cases.
Hope it helps.
PCLANTECHSAuthor Commented:
I really wanted to r&r the security chip - however needed to price the job high to cover shop labor costs and the job was not approved.  Thanks for all who responded | tons of useful info in this thread.

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