sony KV-21FT1K tuning problem

[tgx]

hello all, I finally decided to trash my old hitachi and bought a "second-hand" Sony trinitron. The tv looks perfect everything picture sound quality are perfect, but I can't seem to tune some channels? Here in my region are 4 channels, all look acceptable on all other tv's we have, but on my sony I can't seem to tune 2 of them. The picture on these channels is simply unacceptable, snowy, no color, hissing sound. (all channels were found by auto tuning)
Do you think it has a bad tuner? I can return the tv in two days, but I really dont want to, because the tv is otherwise perfect.

[tgx]

oops! it seems that the problem is NOT in my tv, it looks like they have problems with transciever, because on all other tv's in our house these two channels are bad right now!
sorry for disturbing