All about the Roland Jupiter-series

Hi, recently I noticed that each time I switch on my jup8 it enters 
automatically the self test routine (which otherwise needs to be 
initialized pressing both swiches 1,2 and 3 during boot-up).
The problem is that after two complete cycles it stops on the 3d led 
and keeps flashing it. When I play the instrument thereafter it 
seems that sometimes - but certainly not all the time - and not on 
all patches, a middle key (I think the B one in the middle of the 
keyboard) will not sound or will sound with very low level. Can any 
folk give me an idea of what is going on inside the beast? What this 
3d led flashing is trying to tell me? Thanks for any help guys.