Intializing loop for Laserjet Pro MFP 127

[virtualed]

Hi

When I turn on the printer, it goes initializing over and over. 

I cannot print anything, nor make a copy or scan. 

On screen : Attention light and flash before stating "intializing"

see video https://youtu.be/MRVFqyo8WO4

Thanks for any help

[virtualed]

I thougth it was fixed by Super NVRAM reset (ie when booting press alltogether the right arrow and the red cross).

After restarting it, the initializing loop is back again.