Random restart after log in

Hello I'm having really big problems with my sierra installation : It perfectly worked for month exept for a BIOS entries issue (very common with Gigabyte mobo) so i decided to update my BIOS from F7 to F21 and i think all my troubles just started at this moment. The boot entry problem has been fixed but my OSX installation (I've got a dual boot with win 10 and Win works perfectly) keeps restarting for no reason (it look like a power issue restart). I've downgraded my bios back to F7 and tried to fresh install with no succes (can't access the installer or having an issue during the installation before I manually add the fake SMC kext after the unibeast preparation and hold back one of my 2 8go ram stick for the install and replace it after. Then I steel have this ******* problem it restart after less than a minute or more if i previously unplug my machine and press the power button few time to clean "volatile storage" I saw some people having the same problem as me but any of those made me find a way to fix my issue. one example here (i've created new sessions with no results) https://www.reddit.com/r/hackintosh/comments/5uuozk/system_rebooting_after_login/

my specs : i7 6700K GA-Z170M-D3H 2 x 8go Ballistix Sport 2400 Hz ram sticks Corsair CX550M Gibabyte GTX 960 4go Pure rock CPU cooler 250 go Samsung 850 EVO

Sorry for my bad english and thanks for your answers