I have a Technika 32" TV/DVD combi. I have been trying to programme in Chromecast. Whilst the logo briefly shows this soon disappears and am left with a black screen. The Chromecast unit is not faulty as I have no problem installing on other TV's in the house, one of them being another thou' smaller screen Technika combi. The unit is powered from the wall socket and signal from our router is not out of range as the Sky on demand box works no problem. Any ideas please.