Hi,
I had a similar problem. No Asiair wifi following a failed firmware upgrade.
My solution is here : https://bbs.astronomy-imaging-camera.com/viewtopic.php?f=33&t=10762
Basically, if you have an Apple Mac then I recommend ApplePi-Baker for SD card backup and restore. It's much more user friendly than Win32 disk imager, which I couldn't get to work at all.
Hope this helps!