Power-on Authentication fails for EliteBook 850 G5 making it unusable - HP refuses support

[Edwm3]

I own an EliteBook 850 G5 laptop since 2018 (purchased new from a B&H store in NY) and I am using the Power-On Authentication(POA) feature.

To give a brief introduction, POA is a method which requires authentication before BIOS or Windows boot, right at power-on.

The available authentication options for POA are password or fingerprint. I do not use fingerprint for login and I am/was using only a simple numeric password of 4 characters, ever since I enabled the feature. 

All was good until few days ago, when on the morning of November 17th, I had the surprise to see that the password I've been using for so long, including a day before, simply fails; I tried it over and over again, even with CapsLock on/off until I gave up and decided to call HP Support.

I opened a case(5040239385) and explained the situation expecting/being sure in fact, that I will receive assistance.

To my total surprise and disbelief, HP does not provide a way to unlock the laptop.

They said they used to but stopped in early 2019. 

I asked what am I supposed to do and got no response to this question.

Is HP's lack of assistance implicitly saying that their Power-On Authentication method cannot fail?! Then how come a password used a day before is failing now without any change in BIOS or other Windows settings made by me, the only user of this notebook ?! I even tried with an USB keyboard - in case keyboard has broken.

Now really, I paid over $1,600 dollars for a premium product and used it for 18 months so far, thinking I will use it for a few years more of course - that is why I purchased a premium product in the first place.

What should I do now - just throw it away as this is what HP's response implies?!  I do not intend or afford to do that.

I need some guidance/assistance as this situation is unacceptable.

After browsing some forums in search of assistance, I encountered same opinion - HP is too big to care of a small error % with their EliteBooks and UEFI password crashing/resetting/getting corrupted and benefits financially from motherboard replacements instead of admitting they have a problem or responding to a regular Joe out there robbed by his money.

Can any HP manager take this case and do something??? I asked the support tech to escalate but he ignored me.

[Edwm3]

I found other posts and user complaining of same random problem with EliteBook laptops.

https://h30434.www3.hp.com/t5/Notebook-Boot-and-Lockup/Power-on-authentication-and-bios-cannot-acces...

HP Support, please understand that I cannot assume the cost of changing MB for something I have not done.

My Power-On Authentication password worked one day and just failed the next.

I did not change my password or did any BIOS change! I do not know if Windows 10 upgraded the previous day or not as that was enabled automatically.

Can I get assistance to unblock and get back access to my expensive HP product ?