Reply to Kontrol S4 no master output sound

Hi all,

I've got a S4 since 3 month now, but haven't used it for a month or so.
Friday i decided to do the last update.
Since then I've got no sound on my speakers.
The master level leds works fine (blue and red).
The headphone get the sound fine.
But nothing on the speakers.
The audio routing for master is ok.
What I have tested? What can I do?
Please help...

I'm in France for the summer with a weekly nite starting next saturday.
Using a Macbook Pro core 2 Duo 2.53 GHz / 4 GB of RAM and Mac OS 10.6.7

Thanks in advance for your help

Jean