Hello guys. i can do plumbing but not very good with electricity. In my flat there is a extractor fan Ostberg, article number: 7540001 type LPK 100A in the ceiling. All of sudden it is stopped working. On the instruction and maintenance paper it says to check first the impeller is not blocked or change the capacitor. It does not say how to do that though. Does any of you can guide me through it please? Thank you very much for your time.