Hi,
I had such blob and wrote: Extruder blob - filament blob on printhead.
So clearly I remember that shocking moment when I saw it the first time.
As there was nothing on the Bambu Forum I searched around the internet a lot.
Conclusion out of that: if you can’t heat up your hotted anymore - like by sensor failure. You have to CAREFULLY heat up the blob by other methods. You can find hot air blower - wich is kind of dangerous as it might melt further parts of your printer. Or use soldering iron. Luckely I did not need that but I assume heating up the metall of the nozzle if reachable might help to get most of the blob removed easily. I just can give the advice to stay patient, act carefully and use not much force - if the blob is warm enough it will come of easily - be careful of course it will be extrem hot in some parts.
I had that blob experience twice after, lucky me on an earlier stage as I was randomly looking at the print. I can tell even stairing at your prints will not hinder the printer to create such blobs as you need some seconds to realize what is going on and than you try to stop the print in a hurry which is normally taking longer than you expect. Plus you don’t want to run the printhead in the stop position over the p*** shoot as the hot blob might damage more than already is damaged.
Basically I think this “watch your print” advice is kind of not realistic and will not prevent this event from happening - may just make it less terrible.
If you still have trouble to remove the blob - let us know here. I will try to find the other tutorials that I found for this topic.