MK3s working on First layer calibration but not printing
Hi there,
I hope someone can help with the problem I am experiencing with two of my Prusa i3 MK3.
I am experiencing these issues after I relocated my equipment.
Both printers stopped working after printing a few layers, on both printers the extruder kept moving without extruding any material at all.
I checked for a clogged nozzle, cleaned both of them, reassemble it, and did the First layer calibration. The first layer calibration works alright on both printers.
I experienced issues when sending a print.
When I send the job on one printer, it won't work after the Calibration.
On the display, I see the following message "Please press to unload the filament".
I don't know how to go past that, I already disassembled the hotend and everything seems to be fine.
The second printer instead will start to print the job but the filament won't come out properly.
The first layer won't stick properly to the printer bed and it comes out as dotted line rather then a continuous line of pla.
I also disassemble this machine and everything seems to be fine, the nozzle is a bit old and might need replacing.
If anyone has had the same issue and can please give me advice on how to address both issues I would be very grateful, as I have already tried everything I know and it's not working this time.
I attached the photos for the first printer and the nozzle of the second printer to check if it needs replacement.
TIA
Fran 
RE: MK3s working on First layer calibration but not printing
On the first issue, switch off the Filament Sensor in the menu and load filament manually with "load filament" and "unload filament" commands. If this solves the issue, them your filament sensor is acting up, most probably the mounting scree holding the sensor lid in place is too tight. Unload filament, enable sensor but not the autoload function, stick a piece of filament in the extruder. If the sensor status in the support mwnu reliably switches between 0 and 1 when inserting/removing the filament you have found the correct amount of rightening the screw.
I try to give answers to the best of my ability, but I am not a 3D printing pro by any means, and anything you do you do at your own risk. BTW: I have no food for…
RE: MK3s working on First layer calibration but not printing
I just checked the Sensor status, the IR looks alright but the FINDA is on N/A.
Might this be the cause of my problem? Asking as the printer is not working yet