Nighthawk M5 (MR5200) No Wifi No Wifi anymore

Hi all

I occasionally used my MR5200 for months and it worked well.

A month ago,  it was working well two.

But now, without making any change in configuration, it does provide any wifi signal.
I tried to reset it twice. Even with default parameter, it does not work.

USB Tethered to my PC everything is ok. Connection is perfect.

Does anyone can help me please ?

Best regards