Sorry, I cant help you but I have exactly the same problem, it usually starts about one hour after switch on. I then have to switch off or unplug for a long time before checking to see whether back to normal. In addition to the original problem, I have difficulty obtaining a picture when I resume power, the blue led barely glows...often I have to wait overnight before the tv resumes normal service and then the whole cycle starts over again. I will not be purchasing a Goodmans product again...cheap is not always cheerful!
Ken, April 2009