Bought my 78 Rev C from Amazon.com on the 29th of April. A few weeks ago the sound and alerts started acting goofy. The audible sounds are very week. You can't understand the voice at all. It seems to be still picking up signals ok and the leds work ok. Has anyone ever had this happen to the 78 or any other whistler?? What route should I take to get this fixed? What kind of costs are associated with repairing a radar detector? Is it cheaper to just get a new one?