I also have exactly the same problem. Less than three years old. Did anyone manage to solve it?
Clare Fields
December 2008
I have exactly the same problem. Did you get any answers? I't looks easy enough to change the fan, but i cannot find the parts and I may have to refer to the after sales service team.
stuart WIlloughby
March 2008
I can answer this question...
how can i fix my siemens microwave model hb86k.70b?