TV with no sound or picture.

TV with no sound or picture.

Panasonic TH-50PC77U 50" plasma TV with no sound or picture. Red power light comes on when remote power button is pushed, but no picture, no sound. Menu display works perfectly and scroll through all the various options. Replaced control board that has the HDMI connection about 9 months ago and the TV worked like new until last week. No clue what's wrong.

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