Samsung LE26R73BDA fault?

My tv now refuses to work on digital mode. The terestrial TV works fine. The Digital mode is stuck on BBC1 and will not change channels. When Digi mode is selected the number 1 in a blue bar appears at the topof the screen but refuses to dissappear. (it used to go after about 10 secs.) some times the screen is black. It will not allow me to call up the digital menu to tune the set in. The set is 3 years old. Any ideas appreciated.