sdj60x amp not work... need electric wiring plan

Hi there...- one of my sdj60x amp speakers not work anymnore after a short period of electricities on-offs. The white light also not lights up. I checked the built in fuse but...it is okay. I don`t hear any sound from inside so I guess the problem is a no-function of some maybe even small piece... (excuse my bad english.. i am from germany n long time not practise speaking/writing english) ...Unfortunately the only person still working by old-school system and handcraft wasn`t able to locate the problem and could not find a wiring map... So at least I am in need of some information where to get an electric wiring plan or the adress of a certified repair-shop in germany. Any information would be welcome... thx... T.