Hello, ... may be the internal cabling/routing went wrong? Have a look on this with the command "edasp", there you click than on the "Default"-button. Please let us know, how you set up it, ... maybe something went wrong. Also, change your title of the question, ... Which kind of probe do you use? Which pulsprogram do you use? Varian, JEOL or Bruker? Ok, you gave a hint, with "zg" it is a Bruker one! 3d are measured normally as proton detected ones - inverse probes! solid state is a direct detection one, less proton sensitivity and there are filters in the HPPR, to stop protons in the x channel. Please remember this, and this is the reason to look on the internal wiring scheme with "edasp". Please give us a note, what are you doing. Yours sincerely, Ulrich Haunz