Thats extremely strange. all the screen should be outputting is the resolution and refresh rate. But I guess its possible for it too not send an output to specific screens. The freezing is a bit strange. I Honestly I couldnt say what it is, but to freeze on start up, especially when it was tried on different SD cards.
What do you have attached as far as USB devices go?
Sounds more like the power supply issue that several others reported already. I had the same behaviour, LEDs lighting up for a few seconds, but no signal on screen, no boot.
In the end I succeeded with a stronger power supply, try that if you have one available.
I really don't know what happened but I left it off all night at home then brought it to work so my colleagues could see it too, we used the same supply and it worked straight away.
Maybe the cause is some wiring gone bad in my bedroom, I'll have to check later.
Thanks anyway for the responses!