I had the very same thing happen on my Matrix-6R. You need to go in and first try swapping the positions of two voice chips. Have you watched the dots at the bottom of the display to know which is different? Say the bad one is #3: you bravely open up your obie and locate the voice board. The boards Bythe way are very clearly marked. There are six 24pin chips lined up in a row marked Voice1-Voice6. Swap the #3 chip with another, and keep track since you may need to try more than one swap. Should this technique not work you'll have to find a new Curtis 3396. I'm told the wide ones are available somewhere but the narrow ones are more common. The narrow ones must have their pins gently spread horizontal and soldered to a wide DIP header. This is for someone with very good vision. Email me for more details or advice.mn