Hi, I have installed new printcores on my UM3, but during xy callibration there is no filament extruded from the nozzles. I find this strange, as filament is ok during material load and nozzles are clearly not blocked or anything. I have checked the temperature sensor as well, all fine. I did make a new setup with the Polybox edition II and removed the original spool holder with NFC cable.
But the filament is feeded all ok through the feeders and tension looks just fine, just the regular marks no grinding or anything. What could be the problem? I have not started to test with any prints y