Machine: K40 ribbon cable setup
Firmware: new board
So there is a couple of things here. Since I replaced the board both X and Y are skipping steps. Initially it only happened if I ran over 60mm/s and I was just assuming loose belts but after checking its not. Today the X stepper just started a high pitch squeal when it is stepper active but not in motion. I tried bringing up and down the run current to see if it would make a differences it did not. It both skipped steps and the X also still squealed. So from there I thought it could be the stepper so I took another I had laying around and plugged it into the X where the ribbon cable connects. The squeal went away but it was still skipping steps even under no load. If I went above 60mm/s and with a job that just ran the X back and forth one run would go ok but then the next it would skip half the steps and buzz. So I thought it could be the ribbon cable so I plugged the stepper into the Y and got the same results. So then I tried changing the run current on Y started at .3 and went up to .8 and I got the same results with each.
I am currently out of ideas on what else to try to attempt to narrow down the issue.