I recently came across this story--http://globalnews.ca/news/3613170/winnipeg-woman-speaks-out-after-husbands-heart-stops-aed-malfunctions/ the ran through details regarding an SCA event that took place in just the last week or two.
Essentially, an off-duty fireman spending time with his family and some colleagues of his was hit with an attack that dropped him immediately. While he couldn't have really asked for better company to face such an event in his life (after all, how many are "lucky"--and I use the word loosely--enough to have a cardiac event in the presence of trained EMT's?), not everything went as smooth as possible in this type of emergency. Namely, the AED at the family entertainment spot where he was visiting wasn't working despite being present. Obviously, a non-working unit is no better than not having one at all.
Fortunately, this particular story ended well. The man who suffered the heart stoppage was able to be saved largely due to the quick thinking and reactions of those around him, and it appears from the article that a full recovery was made.
I thought this was worth drawing attention to as it seems it's far too common that AEDs are not properly maintained, or in some cases are older models that may have had manufacturer issues. This article on the occupational health and safety site also mentions that locations having AEDs present that don't work could be risking legal action. While I'd never come across that before, if for some reason an organization needed an incentive beyond saving a life to properly monitor, test, and keep their AEDs up to date, that's probably as good as any.
I also found this article on the sca-aware website that brings in a host of data (albeit a bit outdated at this point) covering the number of fatalities related to poor AED maintenance. If you're interested in digging in further there's a whole host of great information there.
Finally, I just wanted to express that I feel for the family above and hope that the location that had the incident and identified the malfunctioning unit will be vigilant in its maintenance. It must have been quite a hit when the family discovered the AED unit that should have brought their husband/dad around quickly wasn't working properly :/.
I'm glad this story ended ok!