I suspect that the VFD itself has failed. There are circuits inside the glass, and they have been known to cause problems with with columns failing. But the FAQ reference for this seems more that it is literally half the display instead of interleaved.

Can you take / post a photo of it? Also, isn't there a fourth fuse somewhere? EDIT: Nevermind. It is two fuses plus one in a different location, not three plus one like I thought. If all of your fuses are good, all I can think is that the VFD (or perhaps something else on the display board) has failed. If you have a spare player, can you swap in a different display module?