I would like to know if anyone has come across this type of problem, and how to
fix it, if it's fixeable...

We were doing a recording session when mains power was suddenly shut off by
accident. This was a live gig and a previous track of 12 hours was recorded, as
well as a new track which had about 20 or so hours accumulated when power
failed.

Upon returning power, the first 12 hours track was still there but another
three tracks appeared, with no sample rate or word lenght indications. Pressing
''Play'' gives no result, track won't play.

Is there any way to recover the data? This is a major issue for us and
ressources for a solution is not a factor.
I was told that a data recovery facility might be of help but Alesis informs me
that the OS is proprietary and therefore not available...
Any clues anybody?