With Ubuntu 18.04 (installed and/or usb boot), 18.10 (usb), 19.04 (usb) and linuxmint-19.2-cinnamon (usb), I cannot boot my NUC.
Initially, the (Ubuntu 18.04) box started fine, but after a couple of months, occasionally the box would simply stop. Shortly thereafter the linux versions mentioned above will now not even start.
So, under no circumstances, can I start the box and get to a console (except for Advanced Ubuntu startup options ... which leads back here anyway ... the startup just dies).
Here is the log as far as I can capture it visually before we are dead:
tpm tpm0: A TPM error (378) occurred get tcp per allocation Couldn't get size: 0x000000000000000 /dev/nvmem2s1g2 recovering journal /dev/nvmem2s1g2 clean .... files, .... blocks
And my configuration is:
Intel NUC BOXNUC8i5BEH2
Samsung SSD 970 Evo M.2
Corsair Vengeance 32GB DDR4 SO-DIMM K2
I am not able to access the BIOS directly, only Visual BIOS (which has security boot settings, but nothing that reads as "TPM specific" - unlike other posts for this or similar problems).
Need a lifeline :)
Many thanks for your instructions.
After removing the jumper and rebooting, and following the selection of option , upon subsequent reboot, I needed to then also select option  'Suppress this menu until the BIOS Security Jumper is replaced.'
This allowed the box to reboot with the USB stick (19.04 specifically).
Once in, I started to back up files that were important.
But, then, mid-stream, death struck once again.
And, then the game repeated many times.
I re-inserted the jumper in the 1-2 position and, as expected, the same game continued.
Maybe I simply have a lemon NUC.
I will return it to the vendor and obtain a refund.
Many thanks for your help.
Yes, I did.
But, to be sure, I repeated the process completely, unfortunately with the same results.
This box seems to be faulty, since I have not found reports of this problem persisting following these changes to the bios.
It looks like I will need to find another suitable home for my SSD cards.
Many thanks for your time all the same.