Kenwood HB890 stopped working

I have here a recent Kenwood HB890 handblender that suddenly stopped working. When I opened up the blender I found a soldered fuse that was blown (3,15A slow 250V, I'm in Europe by the way). Replaced the fuse but when testing the blender it blew the fuse again and what's more, I saw a spark coming out of the motor (still had it out of the housing).

I then soldered a jumper wire instead of a fuse and took out my variac to test it at a lower input voltage (tested at 140V, remember I'm in Belgium where mains are 230V). When testing the blender I can see firesparks coming out of the motor (though the motor doesn't turn at all!), well it looks more like what you see when you are welding, but a lot smaller. The sparks are located around the coal brushes and only on one side. I know what I'm doing here is not healthy for the motor, but I just wanted to know where the sparks were coming from.

Anyone any idea what the problem is? The coal brushes still look good and still have enough life left. I can also see two components attached to each coal brush. One is a capacitor, the other component is in heatshrink so I can't tell what it is (thermal fuse? a resistor?).

Any help is most welcome!