The attached doc gives a quick overview of how to reset a tune file to default on a 5973 or 5975. The screen captures attached are from a 5975. Keep in mind the folders with differ slightly for the 5973. The default tunes for a 73 are found in the msdchem/mssetup/5973 folder. You would copy to the msdchem/1/5973 for the active folder. All other instructions remain the same.