Hello colleagues of I repair, I get a panasonic tv slim screen model tc21rx30lp The problem it presents is that after 40 minutes of switching on it is put into auto-programming mode of channels and stays in that state without beginning the channel search, at that time it does not respond to the remote control or the front buttons of the same TV. after 2 minutes of being in that state without tuning any channels and only with the letters of "tuning channels" on the screen it turns off by itself . and does not turn on by any means. it must be disconnected from the power for 2 minutes and it just comes back on again, running all right. The fault is presented again after 30 minutes +/- and the self-programming does not come out and is paid. at another time it turns off and turns on alone. Clean the entire chassis because it was covered with dust at the end, touch up the welding of the micro jungle and areas where it might be needed. but it continued presenting the fault. A detail that I could observe when I got the TV is that it has the cushion effect slightly in the image but only in the upper and lower parts of the screen. What could it be, what test should I do? Thanks for your answers

control the keypad well that there is no activated button if the keypad is good replace the memory