Little update/issue
The story :
I had just wired up some few things on my mobo, and
it didn't work anymore
So... I desoldered all the stuff i added (player one... I spent 1 hour on it
) and... STILL DIDN'T WORK
So I started to play with my ground connection (only thing the wasn't soldered, that I just "put" when I needed it) and found out something strange...
If I power my gamecube (on the wall) with the ground directly soldered to the mobo (since the moment I put it on) it works... BUT, if I start the power adaptor, and THEN put the ground connection it doesn't work
So, if someone has an explanation, I'd like to know it... I've never seen such a thing... Maybe putting the power suddenly like this change the voltage on the power board (going from 1.9V to 1.4 or something like that) and the main chips can not start up...
Anyway, it refused to start up with P1 wired up, I'll give it another try this weekend.
EDIT : going further in strange things... It now works normally
(I'm really disappointed)