Can someone out there help me. I have a problem with the amp on my 550. The standby (red led) is flashing on and off. If you press power, it changes to a steady red light. If you press power again, the blue power light flashes on and off, and the display cycles through the inputs, and then the unit switches off, and the standby led starts flashing again. It does this ad infinitum. I have tried rebooting the microprocessor, and checked that none of the speaker leads are shorted with no joy. At this point, the manual contains nothing further of any use. Any ideas??