Thankyou for replying, Americanaudiophile. It turns out my TV is a really old one with only coaxial cable in. My brother managed to connect that to the VCR, and connected the VCR's red/yellow/white sockets to the HDTV box. It worked fine for a bit, but while we were mucking around with other buttons suddenly the picture broke up and we haven't been able to get stable pictures since. I've got the HDTV to retune the chanels but all the chanels are still broken.