I had a problem with my Ender-3 Pro where the extruder for some reason stopped extruding, messing the print up. I tested it out by printing a circle with just one layer.
Turns out the problem was with the extruder driver not being able to push the filament in to the nozzle. The spring needed to be tightened, so I printed this out (with 95% scale to fit my printer) and that fixed the problem perfectly.
The remaining problem is that on some points the filament does not stick to the bed, but that’s just another issue I need to resolve. I posted this here to help out others with similar issues.
The quality improvement of above fix is amazing. Here’s one more image: