Ok, last night I was thinking about your issue trying to figure out a way to verify that the problem was past the menu, thus isolating the issue.
There's a service menu in your TV set that is a very very good option of displaying a full test pattern on the screen, but I ran into a problem with the DETAILS of your service menu.
On plasmas...if you access the service menu's main screen, there are one or two "sections" that should have a "pattern" section that you can highlight, then use the menu's right arrow button to advance through several different patterns. One of those patterns would tell us --
A] The problem is in the video board
B] The problem is in the Plasma panel
That's the whole point of this. Either it's fixable or it's too expensive to fix.
I've looked at a couple "A series" models to see if any of them had good instructions on how to show you WHERE in the menu the Test patterns are.
Samsung is pretty consistent with their location and there's really on two types of service menus they created.
In the OLD DAYS of HDTV...they had a fully unlocked service menu, and in the Later days they locked part of the menu, and in the most Recent models (maybe 2009?) They put some of these adjustments in the customer menu so customers wouldn't access the service menu anymore.
I don't know the exact dates....but I think you may own one of the "middle ages" TV.
There was a code for 0000 accessibility, but when you LOOK at the service menu, you usually see some settings GRAYED OUT when first accessed.
And that's the KEY.
So.....turn your TV off. Follow these Visual instructions to gain access. Read all of it first, It should only be 3 pictures merged together. You only have to access 3 levels of the menu for test patterns. and the FBE and PDP menues should have them.
PDP is the preferred test patterns.
Is the lines seen on top of those patterns??