I found the section in the wiki which is handling the cleaning of the ams from broken filament. But there seems to be one case missing: If the broken filament is not in the sections shown in the video for “Error HMS_0700_2000_0002_0003: The AMS slot1’s filament may be broken in AMS”.
In my case the LED on slot 4 stays red if the filament entry and the ptfe tube are empty. So it looks as if the second stage sensor detects filament. Is there a possibility to clean or look inside the internal 4 to 1 hub?
Yes, I have seen the six screws, but because of the spring I am not shure if the hub should be opened? If you say “be careful” it sounds a little bit like "it should not be opened. Maybe you can give me a hints what could happen?
I have looked a little bit further and it seemed to me, after removing the internal ptfe tubes from the hub, that slot 4 is the only one, where a piece of filament is blocked earlier. I see this as a hint that there is a piece of filament in slot 4 of the hub.
Hi, you can see the relevant part behind the wiki link in the answer from Lucyna.
The relevant element should be step 4 there. For me it was enough, to remove the 6 screws and to lift the movable part a little bit. Then I could see the little piece of filament and remove it.
As Mendelevium mentioned, if you are not careful there are some loose parts inside which could fell of. This is the risk you have to take.