Currently Being ModeratedNov 16, 2013 6:43 AM (in response to Emilio!!)
Same problem here: pressing F10, F11 and F12 has no effect on the sound output of the integrated speakers.
No solution sofar.
Macbook pro 2010, 2.4GHz, Intel Core Duo, 4GB RAM. OS X 10.9.
Currently Being ModeratedMar 4, 2014 6:33 PM (in response to Emilio!!)
Same with me: can control sound with everything but keys. Using 10.9.2 on MacBook Pro 17"
Still seeking solution.