JVC- GD-V4211PCE intermittent screen problem

[lostin the woods]

I have a JVC GD-V4211PCE plasma monitor, i have a intermittent screen problem.

When turning the Screen on its fine, but once it warms up, i get a series of vertical lines, split in half, but scrambled, into two separate sets of lines. one top half of the screen, the other set on the bottom.

At this point it is still showing as a picture but just a scrambled mess of lines, being split into two distinct display patterns of lines.

If you gently hit the rear casing (not sure how someone can actually gently hit a plasma but there you go) the picture will revert to normal operating for a random amount of time, before it does it again.

I'm thinking its a dry joint due to the nature of the problem. the Monitor has 4 fans across the back of the set to suck hot air out, yet the screen still gets fairly hot across the back.

Id like to know what people think about this, as i really don't want to be paying someone just too look at it and tell me what i already think is the problem.

I'm thinking the dry joint upper left hand (if looking at the screen) as it only rectifies the problem if you hit in this area (on the back).

I found a service manual for the GD-V4210 but not the GD-V4211 but it lacks the depth to know what part might be causing the problem.

CLICK LINK TO SEE PROBLEM

when its warmed up it looks like this

http://i182.photobucket.com/albums/x207/Finmerephotos/DCP02420.jpg

if the image is moving both sets of bars move independently of each other, as in, if you have a mouse pointer on the desktop when the Monitor is in this state, you can tell whether the mouse is on the top of the screen or the bottom of the screen, on the left or on the right.

http://i182.photobucket.com/albums/x207/Finmerephotos/DCP02421.jpg

Its getting image data, but its just scrambled, the sound is fine though,
The OSD shows as yellow bars, so you can not access the menus when its scrambled.

You can even change aspect ratios with the screen like this and the lines will display the aspect ratio you have changed it too

Any reply / help would be most appreciated.

Regards