What could be the problem based on this video?

Ender Series Creality Ender-3 S
1

Hi Everybody,

I have an Ender 3 S1 Pro that I use for hobby printing. Today it suddenly stopped extruding filament correctly. I ran a print that already finished successfully twice. I attached a video (as a google drive link) that shows how the black cogwheel jumps and makes this clicking noise.
I took off the hotend, but there was no cloggage.

Thank you for your help
Benedek

2

It turns out, there was a cloggage after all. It was in the nozzle. I changed the nozzle and it started working again.

It wasn’t as obvious though, because I put the nozzle on a soldering iron (200-300°C), and the plastic flew, which I though is an indication that it wasn’t clogged. Despite this, changing the nozzle solved the problem.