100% it is the ribbon in this case. I had the exact same problem, and I ended up at this post a month ago. I ordered a ribbon from Amazon and it did not work (did not even power up afterwards). I ordered a ribbon from Zortrax this past week, and it just came in today, and it worked. It is not the hot end specifically because the gear sticks without any filament in it. So, it has to be something with the gear or something controlling the gear. I first tried what the poster said by checking my connection, but no luck. I took the thing apart and looked at the gear for crud in it. In the end as soon as I turned the unit back on with a brand new ribbon it was good to go. It is crazy that I maybe have 80-100 hours worth of print time and have to put a new ribbon on, but oh well.

Same problem here. 100% sure the extruder cable. I’ve been able to solve it with some tires. I suspect the problem is in the connection and not in the cable.

I am having this exact problem!

when you guys say that the extruder cable is bad, do you guys mean the small cable connecting the stepper motor directly to the breakout board or the flat cable that comes from the main motherboard?

I already tested the small cable that goes directly from the extruder motor to the breakout board using a continuity tester and that all seems connected.

any ideas?

Thanks