Thanks for that I phoned Yamaha's service dept and all the lines were busy.
SPX 90 Reset.
Power OFF
Hold down 'balance' & 'foot trigger' buttons
Power ON
SPX 900 Reset. (not as straightforward !)
Power OFF
Hold down 'parameter right' & 'trigger' buttons
Power ON , allows unit to go through self test until
reaches diagnostics
Using memory buttons go to setting 10
Press RECALL
Press STORE
Power OFF
Leave a moment. (technical bit there)
Power ON
Comment