Latitude 10 ST2 shuts down abruptly

Like many others here, I am the victim of a Latitude 10 ST2 tablet that I bought new, used for less than a week, and when it "updated" itself has become an expensive paperweight. It goes through POST, boots to the first screen, I swipe and get the apssword slot and before I can finish putting it in, abruptly shuts down. This happens with the battery fully charged, with the AC adapter plugged in, every time. 1) In reading through these pages I understand that the BIOS needs replacing, via USB on a thumbdrive. How can I do that when it abruptly shuts down ? 2) I've gotten to see the System Setup screen, but cannot change anything like a boot sequence because it demands the ADMIN password I do not have. I never put in an ADMIN or a SETUP password, is there some default ? 3) I don't know what Bitlocker is or how to find a Recovery Key it's asking for. I do have a Key ID (8 digits) and Drive label, but with no Recovery Key cannot progress past this one screen asking for it. Current BIOS is v.A06 & battery is FWRM8 Thanks in advance for any help. I cannot find answers anywhere on this forum. Anger builds.....