Hello
Here some recommendations from
http://www.sequencer.de/synth/index.php/Reparatur on german repairers in
the north west region. I don't have experience with any of them, but I
can tell about the reports, that are given from the sequencer.de-forum
about those addesses:
In regards of powersupplies it looks like Martin Höwner in Bochum can be
recommended
http://www.synthtaste.de/But according to the reports I estimate him only good for powersupply
stuff and keybed mechanics.
In general Helmut Fischbach near Düsseldorf has a good reputation
http://www.helmutfischbach.comVery wellknown, but booked quite well with a longer waiting list, is
Achim Lenzgen (former technician of Synthesizerstudio Bonn.
http://www.synthesizerservice.de/A local famous guy seems to be Georg Mahr in Krefeld (near Düsseldorf)
http://www.georgmahr.deFlorian