I have a panasonic 50 plasma hdtv (th-50pz80u). I have this recurring video problem. If I watch one channel and never change it, the tv will play forever. If I surf the channels, or go back and forth between two channels I lose the video. This happens if I use the remote or manual tuning. I must wait at least 30 minutes before I can use the tv again. When I lose the picture, the screen will flicker black (no actual video) and the channel identification box will present the information such as number, station call letters, ect. So I end up with a flashing black screen with a flashing channel idenfication box.
I was hoping somebody could tell me if the tuner board (tnph0721a)went bad or whether it might be some other issue. Such as a buffer board, sd board, su board ect. to name a few. Thank you inadvance for your attention to this matter and help. Yes I am out of the warrenty by 2 months.
seems like there is a video mute circuit that comes in on channel change .. I would guess from the fault mode that it's a bad cap or a bad connection on a cap or resistor. 30 mins suggests something is charging or discharging. Mute circuits are controlled by electronic switches.. +v or -v or grounded, only 3 states a control pin on a gate can be at.. on, off or floating.. a cheap way to make a gate stay open or closed for a short time is to charge or discharge a cap connected to the line controlling the gate, very likely in this kind of case run from the tuner control (channel switching) line.
