via this auction
"This machine is an late-made American-made model with Aftertouch, in incredible, serviced condition. It has always been a studio machine, and looks it. I had it fully overhauled by Analogics in 2015, which included preventative recapping of most capacitors and clearing the ubiquitous CPU error. Since then it has performed flawlessly--all buttons, knobs, and keys work perfectly, and the display is bright. The only technical aspect to mention is some minor transformer hum, which is common on all Xpanders and Matrix-12s.
And not only will you receive a 100% working unit, I will also include all the critical spare parts I have acquired over the years. This includes, 10! hard to find CEM3374 chips, 9 x CEM3372 filter chips (matched to the current revision inside the machine), several NOS replacement buttons, AND hardest to find of all, a brand new drop-in screen replacement. These were made a few years ago by and English company--they no longer make them (I got the last one!). Given how reliable this machine is, you will unlikely need to use any of these parts in the near future, but they will be there in case you do. Also comes with its own custom-made hard case."
