Light does not go after installation of new lamp

Hello I’ve had the REX Rs Classic 2009 for 1 week. The light doesn’t go off to the dealer. He soldered a couple of cables and put a new lamp in. After that, however, the light didn’t work again 1 day later. Besides, it starts badly over E starter. The dealer said that something with the ignition was defective and it would cost about 100€. Has someone experience what it could be. Unfortunately, I have no idea of Rearatur in general. MfG Lano09