I was wrong. The messages was "BANK0 INVALID". When I realized my error, I found the solution. Excuse my haste in posting.
Glad you got it sorted!
Out of interest, do you remember how you got to the
BANK0 INVALIDstate? What was the 'wrong tool' you mention?
BANK0 INVALIDusually happens when the memory area containing the Espruino interpreter itself has got corrupted and so doesn't match the CRC that's stored.
I used the wrong tool to update the firmware and now cannot connect or reboot. The screen only shows "BOARD INVALID" and "BTN1 = REBOOT".
Is there a way out of this state?
I have tried holding buttons 1 and 2 down until the buzz and holding them down until the equal signs begin to run across the screen.