You may want to go ahead and order some blank eproms as there is no guarantee the removed bad rom will erase or be able to be programmed correctly.
I had a background graphics issue on my dig dug and it turned out to be rom 114. Both 114 and 115 are the graphic roms so I am pretty confident you are on to the fix. After rereading my thread, it appears likely that the self test does not verify these roms.
I had a background graphics issue on my dig dug and it turned out to be rom 114. Both 114 and 115 are the graphic roms so I am pretty confident you are on to the fix. After rereading my thread, it appears likely that the self test does not verify these roms.

