LG RU-42PZ90H screen issue!

[holmesuser01]

Hi gents.

Working on my first plasma flatscreen. Picture is good, color is good. Near the center of the screen is a 2" or so wide black stripe from the top to the bottom of the screen. Sometimes, it will light up this space and look fine, but most of the time this bar is present.

I've got the back off and have tapped around the circuit boards, and it made no changes. This bar is there on all of the different function settings.

I'm an old NTSC repair guy in real life.

Any ideas? All will be appreciated!

Bruce