Can't simultaneous heat bed and nozzle without error?
I just assembled the MK4 Kit and checked all wiring for damage and checked some of the resistances of the components to what Prusa specifies without finding any issues besides a slightly marred thermistor wire on the heat-bed.
The error I always get is described in this link https://help.prusa3d.com/article/heatbed-port-overcurrent-13309-mk4-21309-mk3-9_405612
I asked support a few days ago about the Overcurrent Issue I was having and they told me to check the wiring and all I found was the thermistor wire was slightly marred. The person helping me concluded that this was the issue and I am getting a replacement.
I do not think this is the issue though since the thermistor is reading the heat-bed temperature without error every time.
I attached this video to show what is happening...
My guess is the board they sent me is bad and there is a short.
Has anyone else run into this issue or has insight?
Best Answer by dumojac:
UPDATE: Received new board from Prusa support after showing them the above video, replacing the board made the printer 100% working.
RE: Can't simultaneous heat bed and nozzle without error?
I can't offer much help, other than empathize. I also have an MK4 kit assembled and have been running into heatbed port overcurrent issues for weeks. First, the bed heated up uncontrollably. After replacing the xBuddy board, things were fine for a while and then I started getting overcurrent alarms as soon as the bed started heating up. Prusa sent a replacement bed; didn't help. They sent a replacement xBuddy board (again), and now the overcurrent issues happen mid-way through prints instead of at the very start of heating. Wire connections are solid, terminals are clean, the wires aren't damaged... This isn't a complex situation, mechanically at least. Really not sure what else to do. Firmware issues is the only thing left that comes to mind. Trying to chat with support again...
RE: Can't simultaneous heat bed and nozzle without error?
Have you tried rolling back to other firmware? I tried switching firmware and every time I still get the overcurrent issue.
I am hoping it is a firmware issue, like adjusting the tolerance of acceptable current to not trigger this issue, I would hate to have to ship this whole thing back.
RE: Can't simultaneous heat bed and nozzle without error?
UPDATE: Received new board from Prusa support after showing them the above video, replacing the board made the printer 100% working.