Actually I didn't move it, but it does belong here.

Anyways, LNB's are on the dish. The look like this.

See if there's any water swirling around the knobby part. Check any connections not just for ice and water, but to make sure they are secure, in good condition, etc.
Also, you may want to make sure the dish is aligned right. You can go to signal strength screen and move the dish around until you have peak signals on transponders (you may need another person around to do this). If it's signal loss on specific channels call directv to see which satellite it is for channels you're having problems with and check that.