RX100: LCD/Display not working

After two years of usage, my RX100 MKI does not work any more. Or to be exactly: It still works, i can make pictures, its focusing and saving them on the SD card but the display does not show anything. Not at the moment i push the power button, there is just no sign of life at the screen. I bought a used RX100 to replace the screen but same goes for the other screen. I than connected it to the other RX100 and it is working. So it is not the screen. Do you think it can relate to the power on/off error that is wildely discussed here. Or is that a hint that the main board might be the problem?

Best regards,

flippor