I'm trying to connect my ipad to the TV via HDMI. There are 3 HDMI ports on my TV,. I've tried connecting the ipad to all 3 ports on th TV in turn, and changed the input on the TV to the appropriate port. None of them does anything. I am sure I have successfully done this before, and had problems getting it connected then, but succeeded eventually. Can anyone point me in the right dirction please?