Fire stick problem.

Hi would anyone be able to help with amazon fire stick problem – turn tv on then i select the correct source on the tv remote for the fire stick press select and its just a black screen and the only way i can get it to come up is to unplug the power cable from the stick then plug it back in then fine but as far as i am aware i should not have to do this every single time, i have two sticks and both have the same problem amazon did a factory reset but no difference hope some one can help.