I've finished building my yocto, and it works pretty well until i've tried to add a power switch on it (i'm using the ericasynths metal enclosure).
I've soldered the ground cable to it (ground main board -> switch -> ground power board), but it does not seems to be an optimal solution..

On power on, the yocto behaves strangely...so i've just removed the switch.
Now, no sound comes from any output of the machine (i guess i've fried some stuff). The sequencer parts seems OK.
Could you please share with me the first test i should do to start to diagnosie/debug the problem ?
(Measuring Voltage on each building blocks as i did during the building process ?)
Thanks so much!
Alain