I just had the same thing happen to me a few minutes ago. I have had this display for a couple of years. I was working on my system when the power went out for an instant. When I restarted my computer the screen was black. I have dual monitors, my other monitor (non apple) is working fine, but the Apple Cinema Display is black. There is no change by unplugging and replugging it in or any of the buttons. And like tg60, the only sign of life is the power light. two quick flashes a pause then a third flash, then it is dark for a few seconds,, then does it again.
Odd that is started right after a loss of power. Does it need to be rebooted or something? Any input would be great.