video problem on panasonic 50 plasma (flashing)

I have a panasonic 50 plasma (th-50pz80u). I have a recurring video problem. If I watch one channel, the unit will be flawless for hours on end. If I surf the channels, or go back and forth between 2 channels I will lose the video/audio. It does this regardless if I use the remote or manual tuning. When this occurs I must wait at least 30 minutes before turning on the tv again. When I lose the picture the screen flashes black and the channel identification box (channel number and call letters)repeatedly.

I was hoping there was an opinion as to whether it was a tuner board(tnph0721a) or some other issue such as a buffer board, sd board or su board ect. to name a few. Yes I am out of warranty by 2 months. Thank you in advance for your attention to this matter and your help.