Hi Raoul
Thanks for the post, the 1st issue you will come p against is spares! These have been obsolete for some time now. I'm slightly confused as the Braun units didn't have a light to show the machine was on? Has this been installed as an after thought? The unit (from memory) had 5 screws underneath, 4 were hidden under the rubber feet and usually had a security head. Once these were removed the black base would usually remove or turn enough to gain a visual. Its my guess that if the motor still runs when assemble the belt had broken hence no drive to the main shaft, this you could perhaps see through the vent holes underneath? Call if I can help further.
Jason at SUSSEXSPARES 01273 329898, November 2014