My Panasonic TC-L55DT50 turns on but can barely see it

George Stevens, sound to me like you are having a backlight issue. Check this first:

"LCD Panel test mode

Purpose:

To find the possible failure point where in LCD Panel or Printed Circuit Board when the abnormal picture is displayed.

How to Enter:

While pressing [VOLUME ( - )] button of the main unit, press [OPTION] button of the remote control three times within 2 seconds.

How to Exit:

Disconnect AC plug from wall outlet.

How to confirm:

If the abnormal picture is displayed, go into LCD Panel test mode to display the several test patterns.

And then, judge by the following method.

Still abnormal picture is displayed: The cause must be in LCD Panel.

Normal picture is displayed: The cause must be in A board.

Remarks:

The test pattern is created by the circuit in LCD Panel.

In LCD Panel test mode, this test pattern is displayed unaffected by signal processing for RF or input signal.

If the normal picture is displayed, LCD Panel must be okay and the cause of failure must be in A board." To make sure that we can assist you further with your boards. post some good images with your question. For that use this guide. It could be an issue with your P board or the LED driver board.