our original diagnosis was wrong, it isn't the fan at the back thats the problem, its this guy:
the 'blades' thing can slide along its axle and eventually moves itself to the the edge of its cage (to the right on the photo) which causes the horrible noise.
Oven update:
our original diagnosis was wrong, it isn't the fan at the back thats the problem, its this guy:
the 'blades' thing can slide along its axle and eventually moves itself to the the edge of its cage (to the right on the photo) which causes the horrible noise.
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