Hello .. I have a saz 3500d but I have some problems with it! Protection light is on all the time even though I have no bass coupled .. It became like this after I made a mistake with the soil to the stereo so the earth by l rca cables. Have a friend who has a firm that makes amplifiers for home use that have looked at it but he says he must have the wiring diagram for saz 3500d in order to repair it. Can you help me with that? or if you think of something else can help me find a wiring diagram? Or do you have some idea of what it could be wrong? are very pleased with the amp in general and would like to fix it so I can use it! Since I live in Sweden and is suck in English so I run google translate, hope you understand what I write. =) Sincerely Bjorn Jonsson