Samsung hc-p4241w - No picture

The tv switches on, I can see the red power button flashing. There is no melodic chime when it does start up though like it used to. the screen stays black no light from the back of the tv via the colour cannons. There is sound. I have a Sat receiver and a dvd player plugged into a home theater receiver which is then pluged into the back of the TV. I also have an X-Box console plugged directly into the TV. I started getting this problem a couple of months ago. the TV Picture would not come on. When I left it for a day or two I would get the picture back. Now I can't get the picture at all for the last three weeks. Any idea what the problem may be and if I can repair it myself? Thanks.