I'm in the process of setting up some presets on my HD400, lots to learn and apply. Last week I had to travel so I unplugged everything and did not return to my project until yesterday. Upon completing my normal rig setup, I noticed I had no sound output from my guitar. Researching the chain, I had an iPad linked via the mp3 input  that was operating fine and had normal output, and had guitar output in the wha mode of the pedal only. Discovered that the vol pedal required a calibration, and i'm not sure why.  Also discovered that the parameter adjustments, done using the presets knob, are in the coarse adjust when in the normal position and go to the fine adjust when pushed in. Sort of opposite to the way the manual describes the function. Has anyone experienced these issues or have an insight as to what may be wrong?