Heathkit GR 2701 Digital System 3

[tritwi]

Hello everybody! I 'm brand new here and I'm a tv collector from Italy. I deeply love Zenith televisions and amongst the (unfortunately)few I own there is a GR 2701 digital system 3 from Heath company. I think it has a Zenith chassis. Since I bought it new many years ago (1989?)I tried in several ways to operate it on our PAL B/G 50 hz but without any luck! I connected it through a transformer stepping down 220v to suitable 117v but the problem seemed to be the mains frequency (50 hz instead of 60) and the tv remained dark. You could hear just a click when you pushed the on off switch.I injected a 60 hz signal to the power supply with an external wave generator and the set turned itself on but the picture rolled continuously from top to bottom,the color was missing and so the sound. I tried several options available on service menu but without any luck! Is there anyone there who knows if there are secret menus that could change the reception standard and the operating power supply frequency?I know tuner and if stages are quite different from european tv sets but I'd love to use it as a monitor. The set is a huge 27" console and in my opinion is really beautiful. Too bad it never worked! Thanks