Me again, I was reading something about DX21 patches and thought about your trouble...is it possible you've got a patchbank loaded from the wrong synth? The DX7 doesn't really use terminology like 'bank 4' but the 21 does. That's a 4-op machine vs 6 on the DX7.Get some patches (I think you can get the factory patches online. If you've got a sysex editor you're all set.)that you know for sure are for your version of the DX7. If you,re still having trouble it's possible the battery needs to be changed. Under 2.8v it's suspect, under 2.2 it needs to be done NOW. Have a tech do it or there's a spot on the Yamaha Zone with directions for the reasonably skilled or brave.mn