MT1300 Beryl cannot connect to Wifi

I have a Beryl MT-1300. I had firmware 3.216 and used it as repeater. At some point suddenly lost connection with Wifi network, and cannot find any networks. It works with ethernet wan, and with tethering. I tried to install 4.3.7 release1 beta but it still didn’t work. I re-installed 3.215 but it still cannot find any networks. And we are talking even about my wifi hotspot from my cell phone which is adjacent to the Beryl.
Can anyone help? Or is it a hardware problem and the router is useless as a repeater?

That seems like a hardware failure. Have you checked in luci to make sure the interfaces are responding?