apple display 30 inch no power

Hi,

I have an older 30 inch apple display which I absolutely love. high Def, perfect for watching shows, etc. I have my lap top hooked up to it and I use several cables to connect my display to my laptop. It's a nice set up. Today, I unplugged my laptop and when I came back I couldn't get any power to the display. Obviously, the display uses an independent route to draw electricity so it shouldn't make a difference if my laptop is on or off. I should be able to see the blue light turn on indicating power availability to the screen. Today, The blue light at the bottom didn't come on and even when I unplugged and replugged the power cord nothing changed. I think my power adapter (150W) is dead. Or it could be the screen, but I doubt it because I think most display dont die so suddenly. Or do they?

I know that my cables from the laptop to the display are working because when I plug them in, the computer tries to use both screens - I see my laptop screen change as though it's projecting on both screens (the laptop and the display). But there is no power in the display.

Can someone please advise about what to do?

Thanks!