Hi, I have a Yamaha sub YST-SW015 which is 1.5 years old. The first one I had stopped working and had to be set off to be repaired after 5 months. It came back working and has now suffered the same problem - it is completely dead. As it is self amplified I dont know why this keeps happening. The unit comes with a 3 year warrenty from Yamaha. As this is a recurring problem, I am entitled to a new model or do I simply keep sending them back for repair. Has anyone else suffered these problems or know of a solution? Cheers.