tonto.

hi all, new to all this, so please be gentle with me!. i`ve got a 50" panasonic viera plasma tv. 18 months old now, recently developed 2mm vert line in centre of screen. it was intermitant at first... so took photos of problem to show `comets` engineer. tv went to workshop for bench test 2months ago for 1 weeks test.... no fault found. tv worked without problem ever since.. until now! the line is back... but 2" left of centre now, and seems to stay on permanent. i`m calling `comet` tomorrow... but could do with some advice on what it might be so they dont fob me off. `thanks` for any info in advance