I can't get my Raspberry Pi to connect via HDMI to either a TV or a monitor. It will connect using AV leads. I have searched various forums, but the advice is always rather technical and doesn't seem to fit with what I see on screen. Any ideas?
Did you try to set
/boot/config.txt on the sdcard?
If this is not working you can also try
Push the HDMI connector in all the way (it fixed the problem for me).