I was watching some TV as usual, switched off the amp to standby to go and have dinner, came back and the standby light is off and it will not switch on. Is this something fuse related? I was concerned that the plug said it required a 10A or 13A fuse and there was a 5A fuse fitted. I changed to a 13A fuse and it made no difference. Pls help as no TV at the moment!