We've just got a secondhand sony tv - haven't got the remote with me, but think it sounds the same - did you notice the remote sits in a little 'holder' - when you pull it out, turn it over and there's another set of buttons.
I tuned our TV using the 'hidden' buttons on the side with lots of extra buttons, rather than the side where the battery sits.
Hope this helps.
We're having problems tuning so the video works!
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December 2009