Circuit Overview:
More keys and double the ROM memory of QS6, and rev. 7.1 in 1999 adds more.
Service Tips:
Always verify power supply voltages if problem looks like it could remotely be power supply related. I have seen some bad solder problems and one intermittent processor reset problem that required a new board in an Alesis product.
Parts:
Advanced Musical Electronics has a lot of parts for Alesis stuff. THey only deal with techs though.
I've also seen All electronics carry displays occasionally at low prices.