Panasonic Plasma screen interference on left half of screen

[Zelek11]

My Panasonic Plasma model P55VT50 has started displaying "interference" on just the left half of the screen only (left when facing the screen). Sometimes it's concentrated in about the first 30 seconds after startup, then disappears. Other times it's fine at startup and then randomly does it later on. When it flashes the interference it's very quick and doesn't stay on the screen unless it flashes repeatedly in a row.



This image is a screen shot from a video I took. This is an example of the interference at its worst. Often the interference is much smaller than this, but otherwise looks the same and is only on the left side.

Any idea what part is starting to go bad?

Edit: fixed picture upload