Is the AP broadcasting any SSIDs?
Is the AP in AM mode?
Do you have any profile errors?
Is the LED disabled in the AP System Profile?
What is the regulatory domain of the Controller and the AP?
show ap bss-table ap-name [AP NAME]
show profile-errors
show ap active
show ap system-profile [PROFILE
In short, there is quite a few reasons as to why this is the case. If you can run the following this will give us some clues. Also is there a reason why you have ap-specific as opposed to the VAP in an AP Group?