Hi guys i had the very same trouble with my interact 1 with 2500 control the same message came up with spindel drive fault.We tracked it down to the small transformer on the mti board it did get fried ,if you look closely you can see the resin all burnt.I did some very long hours searching around for imformation on the transformer and after finding out the neccessary values,i had a much more heavy duty one made, and fitted it away from the board, on the inside of the cabinet on a insulated pad.And thank goodness she s been running well since.