There are lots of strange things regarding A3000 ROMS.
Whatever you do, do NOT try the ROM's in the wrong orientation, you could destroy your A3000.
What you could try is swapping the chips over (in the correct orientation) sometimes the silk screen on the ROM tower is bad. (Ah I see you have already tried that)
You could try them without the ROM TOWER. Some ROM chips for the A3000 eliminate the need for a ROM TOWER, these go in the REAR set of ROM sockets.