Removed optical drive

Take the system apart again and make sure the WiFi card is connected properly. You have to move and or remove it to get the optical drive out so it seems you did not reinstall it correctly.

It's the thin ribbon cable that goes across the corner of the superdrive.

I spoke too soon. What I described above is a 2010. It may be the cable you're referring to.

The ouline in red is the card its holder and the on card connection. The blue outline is the connections, 2 of them, to the logic board.

imageboy wrote:

Thanks for that tip. I have it apart but it is not obvious to me which is the wifi card. If its the long shrouded cable that runs along the back from one corner, it was very fiddle to get back. Could I have bent one of the tiny pins?

I think you may have this model, where the airport card is under the clutch cover. Does your battery remove as this guide shows?

http://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Late+2008+and+Early+2009 +Airport+Card+Replacement/6274