Rhodes Chroma Polaris

I just got my polaris back from a repair shop that did some surgery to 
replace the assignable slider and swap a front panel that had switch 
problems. ( parts from another polaris) note  It appears that the 
circuits now work and the controls work but there  now is this odd  
DETUNE? problem.  As you play through an octave the notes sound sour 
and progressively more off till there is a ppoint when one sounds 
markedly flat then seems to return to being more tonal by the next 
octave, this occurs on almost all presets, some very bad others less 
so. ( possibly noticeable in all sounds to some degree) I tried 
the 'tune all' voice reset button , no improvement, and also the 
detune slider seems to have some effect but  when centered this effect 
is still present, moving the detune slider modifies it but it sounds 
wrong regardless of setting.  Couild the ossillators be out of sync?  
Is there a way to adjust them? the unit plays but as a friend 
says.. "it sounds like you are playing a sour blues scale when you 
play c major."  so far the repair shop is reluctant to repond to my 
complaints and I wonder if anyone has a clue as to what may have 
happenned.