W7AY means to power the ASIAIR with enough voltage and current, it should be 5V@3A.
However, if you are impatient and still have the image from the original saved file on your computer, you can mount the image file (it mounts as a volume named BOOT) and find a file called zwoair_license (just a text file) in that volume.
If you can see the zwoair_license file, you can copy that file to your new card, and that should allow the ASIAIR OS to boot up completely. While you are at it, save that file somewhere, in case you need it again the the future.
Every ARM chip (like the one used in the Raspberry Pi that forms the hardware component of ASIAIR) has a unique processor ID. Part of that unique ID shows up as the eight hex digit in the ASIAIR serial number. You can see the ARM processor ID by attaching an HDMI display to the Raspberry Pi HDMI port.
From what I can tell, ZWO uses a one-way encryption on that eight hex digits and place the encrypted string into the license file. When the ARM chip boots up, its processor ID is passed through the same one-way encryption algorithm, and the ASIAIR OS compares the result with the string that is in the license file. If the two strings match, the ASIAIR will complete its booting process.
It is the ARM chip's unique processor ID and the license file with the one-way encrypted string that ensures the ASIAIR cannot (practically) be bootlegged.