JeromeAriola:
If selecting the wrong board type caused the thing that read the code to be "deleted" can I just reupload the programmer or something?
So your nanos currently cannot be detected by ANY computer? So if you connect one of these nanos to a desktop computer (eg. Windows operating system PC), then does anything light up? And does anything get detected in 'device manager'?
Regardless of whether your existing nanos have had their firmware corrupted or not, you did mention that these nanos were working just fine with nrf24L01s at one stage. So.... one good test would be to just get a new nano and a new nrf24L01.... connected it all together..... and see what happens. Actually.....before connecting the new nrf24L01 to the new nano......you should first try to get communications between the NEW nano and computer. And then connect the new nrf after that.