I just finished installing the 10.6.5 update on my 2010 MacBook Air using the Software Update utility. The installation process went smoothly but my 2 week old 13″ MacBook Air didn’t come back to life after the restart. It’s dead. No picture, no Apple logo, no chime, zilch! The only thing I hear is the fan when I press the on/off button long enough. During the update process the fan came on (until then I didn’t even know there was one). Maybe some component on the main-board overheated? Just speculating here.
I’m still in the process of trying all sorts of keyboard combinations to reset PRAM and stuff but so far, none have worked.