hi all,i just read this thread whilst looking for something else and it reminded me of a job i did this summer.
i had a similar fault on a mori ZL25 with 11TTF, it had a J on the masterboard on pwr up so i tried a casette from another machine and it booted (with estop in) with an mh50 machining centre pmc.
I desoldered the roms from the original casette and put them in bases on another spare casette and it worked and is still working.
i backed the roms up whilst it was working just in case. i think the casettes fail before the roms.
its the second one i have done this year, the other was an old DSG lathe i think it was an 80's retrofit