V4 board not responding

I have quite many V4 boards and everything works fine. However one board is not responding.
I mean LED light is different, power button does not create any response. It does not create a wifi network. I have connected lan cable, but I could not find the board in the app. By the way once turned on the LED is not blinking, it just is on. The color not blue, its more half green, half blue.

woring board:

not working board:

Perhaps you have an idea how can it force it to restart or smth?

Regards