My Nikon D90 is not getting start. I have checked my battery that is ok. Can anyone please tell me the error and solution ??
You said you were doing some night shooting. I suspect you may have done a long exposure? If so, the camera may take a while to write to the card. If you turned the camera off before it finished writing it is locked up for the moment. It happened to me.
What to do:
Look at the power button and you will see "Off", "On" and then a "Bulb" symbol. Rotate the power switch all the way over to the Bulb symbol and hold a few seconds. Turn the camera "Off". This should, as in my case, reset it and then reformat your card.