Hi everyone.  I am experiencing an issue with my Matrix-12, the first issue it has ever had.  I sincerely ask that our esteemed panel of OB experts please provide any comments or suggestions you can regarding the following symptoms:

On power on, the instrument powers up as usual; display reads as normal.  Hitting a single key (anywhere) causes the instrument to emit a note, but that note sustains and will not stop emitting.  The note being emitted is equal volume out of the left and right 1/4" outputs. 

Then hitting any other key causes the instrument to emit a second note along with the first note.  But that second note sounds "thinner."  And that second note is NOT the pitch that that second key should be emitting.  (In other words, if I hit a C4 as the initial note (that then sustains), and then hit a C3, the second note is not a C3 but some pitch higher than even the C4 note).

Hitting a third key does not appear to emit an additional sound.

Entering another patch number results in the new patch being displayed in the readout, and the sustained note (and thinner second note) now turning off.

However, hitting any key now emits no sound whatsoever. Selecting Master Tune and tuning VCOs, VCAs etc. results in all PASS.  

I can select MASTER and modules as normal, and they display as normal.  Only, no sound now.   

Powering off and restarting results in the same symptoms.

This is a non 12-out model, if that helps with any diagnosis. 

Thanks for your kind consideration.

Michael Padilla