Adding to this-I am now thinking previous owner may have tried to update the firmware and pooched the operating system. Short of buying a new oscilloscope to test the clocks, I think it must go to Yamaha factory service. has anyone here had any experience with this-are they reliable, do they charge fairly? If not I will try to find another tech although good techs for music electronics are hard to find, I've had 2 very poor experiences with "reputable" repair techs who were 1) incompetent and 2) irresponsible. Neither one fixed the equipment I gave them. Only good tech I ever was happy with is Thesoniq in California, but he specializes in Ensoniq products only.
