Fix Bosch DHE645MGB cooker hood?
 
                I have seen another post on this site about a similar fault on another Bosch cooker hood and tried the same process.  When I removed the front control cover (power isolated) I found the microswitch on the extreme right hand side.  I did a continuity test with the multimeter and found this switch in working order.  I can see a white plastic box just to the left of the switch, with power lines in and out, to switches, lights, fans and 240v socket, but I cannot see anything else that could be at fault.  Is this white box the fault and where can I get a new one?
Thanks
Dave
            
             Dave Haynes
            
 December 2013