Thread:Talk:RPiconfig/RPi 3B stopped by advice on ARM7 change to ARM8

I followed the advice to0 change ARM7 to ARM8 on Raspberripi 3 b, but now there is no video output signal, and it doesn't get its lease from the router. I cannot communicate with it when before I could. How can I recover contact? I have reinstalled NOOBs etc, but without success.