Before I call for the repairmen, I was wondering if anyone here could help diagnose the following (see attached images). I've searched thru these forums but haven't come aross the same problem.

SP61L6HXX/XSA (not sure of american equivalent model) with flickering pixels in horizontal and and veritcal lines which gets worse the longer the set is on. Can sometimes be fixed by turning it off for a while then back on. When it's really bad also get flashes of pink and green vertical lines across the screen. Occurs on all inputs (PC via DVI/HDMI, PS3/XBOX via Component, TV via AV) but doesn't appear at all on the blue standby screens.

Any ideas would be greatly appreciated.