I had the same issue as everyone else. A friend of mine who is an electronic technician checked my amp and found that a chip transistor in the connection of the motherboard to the power supply was responsible for the failure. He changed the chip which costed 3.80 € (when the official retailer in Greece asked me for 250 € to change the entire motherboard) and the problem was resolved. My amp works perfectly.
If you know any good technician that you can trust let him check your amp it may be fixed. All the other solutions will only help if you have a software problem.
I hope that this might be helpful.