looking at my manual and misc doc they have, they say "replace the master board"

Well not necessarily. More likely is you lost your ladder and or have garbage in there. My battery was not really dead, showed 2.85 volts but ladder was a mess.

I went through the entire initialization of my VK45. Cleared/erased everything. Loaded new ladder. Still have lots of errors on the screen and PC not ready. Some of the errors said something to the effect of PARAMETER 023,044,...blah blah.
Loaded a good parameter set, now down to one error -- pallet something...cleared it and reboot. Finally have a not ready screen and she starts and runs pretty well. have not done a full run program test but zeros XYZ and spindle changes gear fine and M3, M4 and M5 work

tomorrow, I have to reset the carousel position and next/ready tool, check my "set tool length" location and prob several other things need tuning as well