Ensure that the 5-pin midi cables connect; MIDI/IN ->MIDI/OUT and MIDI/OUT->MIDI/IN (a very overlooked issue) if Mac; try MIDIMonitor. http://www.snoize.com/MIDIMonitor/ (free download) Open "Sources" then "MIDI sources", the mio should be listed here. Ensure that the boxes for these are checked. The window below should display all incoming MIDI data coming from the mio. Windows; When connecting the mio into your PC via the USB for the first time, Windows should recognize the device with a message "Installing device driver software".
Frequently Asked Questions for mio