Help, Goodmans GDB 2 help?

weird one this, my goodmans GDB 2 digital box keeps flicking on and off. What i mean is, is that, i am watching, just say, E4 and it will work for about 2-3 mins and then it will either freeze, (i then have to reset it) or it will turn off. It then turns back on. This has been happening for about a year now and last night i finally lost it.
Please help me.