eryker

Yep, was one of my first steps. I also replaced both limit switches, and the problem persists. I wasn't able to get it on video last time it happened as it occurred when the printer paused itself due to a nozzle clog. The serial cable should help me pin down the boot issue at least.

I have a UM5 running the latest stable firmware. The printer has an occasional issue with movement on the X axis, and possibly also with the Y axis (hard to tell). It seems to occur about every other print I do. When the printhead performs the homing routine, the printer makes a loud grinding noise and the head struggles to move under a high amount of vibration. I've never encountered this during a print, only during homing or when I have to change filament. Once this occurs, when I reboot the unit, it hangs on boot. I have to power it completely off and leave the power cable unplugged for a few seconds. Here are the observations I have made: -Mechanically the printer seems sound. Belts look fine and are tensioned appropriately. Linear shafts are all still in their bearings. With the steppers unpowered, both X and Y move fairly easily without binding for their length of travel. -Limit switches all test good, tested with both multimeter and the onboard diagnostic. -Stepper cables look fine without any obvious signs of damage and are plugged in completely. My inclination is that either a stepper driver is failing or a stepper cable is bad. It seems consistent with a missing phase on a stepper. It seems like it would be helpful to know why booting fails. I downloaded the logs and looked though dmesg, but the last log seems like it was from the second successful boot. Is there a way to ssh in while it's booting? Is there a serial connection I can use instead of the network stack? Thanks for any assistance.