Panasonic th50pz80b wont turn on 3 clicks then 10 flashing light's

SOURCE: Panasonic Plasma HDTV 50

Please make sure your connectors are in the proper place.

The HDMI inputs on the rear of the TV are optimized for use with Audio/Video devices, Blu-ray Disc Player, DVD Recorder, etc.
The front or side HDMI inputs only are designated for PC. To use the TV as a PC monitor, advise customers to use only front or side HDMI inputs.

SOURCE: panasonic th-42pa20 plasma 42 inch tv

Try to replace the Main Power Supply board first.

SOURCE: 10 blinking light.

It is called mainboard and is the one where you plug your video (HDMI,component) cables if you want to order a new one you need your product code, it is located in the back of the TV, same place as the serial number.

SOURCE: my panasonic plasma TH-42700U it turned off while

solution of light blinking

SOURCE: my tv will not turn on. the red light flashes 10 times then pause

Most likely a bad Y-sustain board.