Logic guitar static

I had been successfully recording guitar tracks with Logic Express. I usually use either a Line 6 Toneport usb input to my iMac or a Line 6 Guitar Port. I have returned to recording after a year off and suddenly, I am having a ton of static on the guitar tracks. I hear it as soon as I start playing the guitar using either input and the static shows up very loudly on the recorded track.

I am completely baffled. The identical result happens when inputs are switched, Toneport or Guitar Port, I have checked and replaced all cables. It's not in the guitar(s). I have tried single coil and humbuckers. So, the problem seems to be in the iMac audio or the software. Any ideas?