More keys and double the ROM memory of QS6, and rev. 7.1 in 1999 adds more.
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. If you need to access testing functions etc. press 00 and 0 while powering up. If you need a reset save your data and press 0 and 3 while powering up.
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.Always feel free to ask or check my Parts
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