Some channels have no sound some are in spanish

Question

i have a 27 in. orion flat screen that is only 2yrs old suddenly when whatching tv lately i noticed that some channels are inexplicably in spanish and some have no sound at all i cant link it to my cable it is definately the tv if i auto prog to reset channels it randomly sets in different channels and the language is set for english on all channels the picture has been fine only last night it started saying text ch1 on channel 12 and after about 5 secounds a big black block appears switching off then back to the channel makes it go away for the 5 sec delay