Hi David.
Below is the condition of bones fan once it was taken apart for investigation.
As we know 1.8 fan control lid taken off.
1
Remove the broken cowling for the motor.
2
start of removing the rusty back plate/lid.
3
The back plate lifted
4
Right away you can see burning damage.
5
6
Remove the board holding the brushes, right away you are confronted with the real extent of a stuck motor and the damage caused.
7
8
Here you can see that the low speed brush as been completely burned away, the medium worn down to a 1/4
9
Every brush as hot burning residue marks on them, as well as the wiring wind and commutator.
10
Quite a few of the windings have burnt completely through.
11
The only thing salvageable is the wiring loom & control box, these still need to be checked before they could possibly be used for another project.
12
13
I don't know how this as been missed, you would certainly have known by either smell or noise of it being stuck, lucky escape that no more damage was caused
