IDRAC6 Connection failure after motherboard change

Hi, i just changed my motherboard on my R710 to a new one, then i seem to be stuck in a loop where it says « iDRAC6 communication failed » then reboot. After the reboot it’s says failed again but give me an option to continue (F1) or open setup (F2). This happen in loop. I dont have access to the idrac webpage page or settings at boot, lcd screen in front is always turned off and fan always spins at max. The led behind is always off. All the hardware worked fine before the swap

What i have tried:

-Update bios to latest (6.6.0)

- Reset bios (removed battery) and holding power button

-Reset bios with the nvram

-Reset iDRAC6 with the nvram and holding « i » button for 30 seconds at the front

- Trying with, without and another iDRAC6 Entreprise module, it always give me the same problem 

- Trying to boot with bare minimum (Risers, Fans, 1 psu, 1 cpu, 1x8 gb ram)