Maybe try MASTER>Utils>Tests-Password (1358)>More>InitEE
I think you'll have to use the MASTER>Utils>Recal afterwards but it's easy.
This clears all the settings like a brand new unit i think, it's a shot in the dark - maybe the only thing I can think of....aside from maybe something's come loose inside, a lead into a socket???? Then again no error messages.....try tweak at
http://studio-central.com/phpbb/ there's an emu and sampler forum there, Tweaks got very good knowledge with this sort of thing.