Ok, its possibly off topic so if you don't want to read it turn > away now...
>
>
> We have a c 5 years old 28" JVC CRT flatscreen tv known as a
> 'widescreen'
> I believe. Between switching it off one evening and then on the > following
> day the displayed picture has gone from filling the whole
> screen to just a
> central square in the centre of the screen that fills the depth > of the
> scree but has a significant black border down each side of it.
>
> I have gone to the menu and tried to change the aspect but none > of the
> settings (panorama; 16:9 or whatever)make any difference to the > size of
> the visible picture.
>
> I'm now under orders to get a repair man in to chack it out > but, before
> doing so (in case I'm missing something really simple) I
> thought I'd seek
> a solution here first.
>
> Thanks for reading through and any suggestions will be
> gratefully
> received.
>
> --
> David
>
You have a line scan problem - TV man required, sad to say.
If you live near a Comet they have a network of repair centres, albeit it will take about a week - 10 days.