I am working with i3 Mega printer.
After more than a year printer sopped working as intended.
During the print filament stops flowing.
I did replace extruder and bowden from the spare set.
Stepper motor that feeds the filament starts to skip at some point.
Filament is perforated by the gear to the point when it breaks.
At the same time printer is reporting correct head temperature.
Printer finishes print successfully, at least it thinks so.
Print is half done and I can see that the filament was flowing slower and slower to the point when it stopped.
How to trouble shoot my problem, what can be the reason for it?
Solution was somewhere else. Here is the topic that helped me to solve it:https://www.thingiverse.com/groups/anycubic-i3-mega/forums/general/topic:32232
Problem was caused by dense support and retraction setting.
If you already have changed the complete hotend + the extruder seems to do the job to push the filament and you get the same problem the issue might be the filament itself. Low quality, variable diameter = get stuck.
What happened to my I3 Mega is that the extrusion motor overheated. The pressure wheel and the filament got too hot, the filament got soft, deformed under the pressure wheel, got damaged and didn't go in any more.
Maybe it's a symptom of something else (a beginning obstruction in the heater or so), but in my case I noted that the extruder motor wasn't moving smoothly anymore (remove the motor from it's frame and check how it's moving). I disassembled the motor and replaced the bearings.