your mag may be set too low with it's resolution setting. The TV if newer, prolly will not recognisea low resolution setting. So get into your Mag's Video and resuolution settings and take notice of what it is set at and if at 480i then increase it to at least 480p or higher
Or it could simply be a bad HDMI cable or weak connection. Or your TV does not recognise that spacific cable (the brand of the cable can make a difference).
