I would first check what typical membrane switch problem you can read about it in previous posts in this group

On Oct 10, 2013 3:08 PM, <c.puidokas@...> wrote:

 

Hi Everyone!

How are you doing?  I just joined this board in an effort to have my Chroma Polaris be something other than a heavy paperweight.

I'm trying to diagnose the problems that my Polaris is showing.

So far I have done the following:

~ Plugged it in and tried playing a few notes - there was sound with a few keys, but it only registered the same note each time and on different keys and constantly alternating keys.  Some of the slider controls affected the sound (Attack, release, and decay), but others were unresponsive.  

~ I then attempted to run diagnostics using the lower function and program select buttons.  However, I was unable to engage the lower function LED rendering a diagnostic scan impossible (at least from what I can understand).

~ When I turned the Polaris off and on again different sets of LED's were illuminated 

My question is: could this be symptomatic of a dead battery/erased memory requiring a new set of batteries and MIDI sysex dump, or something much more complicated?  

If anyone has any advise OR just wants to buy this broken synth from me to fix it themselves contact me.

Thanks,

Chris