I've been having this issue for about a week now. I turn on the Xbox and the light comes on but no signal is displayed on TV. I've tried the Eject + Power button as well as all other suggestions on the Microsoft website and it just wouldn't boot. And then today I tried it again, and magically it booted up no problem. So it didn't work for days and now it works. Has anyone had any issues similar to this? I'm not in the Preview Program and have the current firmware version. Maybe the hard drive is dying?

Try a different HDMI cable.

Second trying another cable if you haven't already.

Try a different HDMI port?

I've tried different Hdmi cables, ports, and tv's. I switched it to energy saving mode instead of instant on and will see if that solves it.

Have you called Xbox Live by now?

1-800-4-MY-XBOX

The hard drive might be it, yea.

@blu3v3nom07: Not yet. My warranty is good until October. I'm going to give another week or two and see if the problem persists, then send it in.