Arduino Nano not working - Power LED blinks 8 times, L blinks 7 times

I bought three arduino nano clones. The "REXQualis" ones on Amazon.

I'm running OSX Catalina. Arduino IDE up to date. But they don't work.

Specifically, they don't show up under my Ports in the Arduino IDE.

Was told I needed to download CH340 drivers, so I did that.

They don't work.

Was told I needed to delete them bc Catalina has it's own CH340 driver and they conflict. Deleted them.

The nanos still don't work.

I've tried every other basic troubleshooting answer: different ports, different cables, reboot, re-install, etc etc.

What DOES happen, is when I plug in the nano via USB, the power LED blinks red 8 times, and the L LED blinks red 7 times (both at roughly the same time).

Does anyone have any ideas on what else I could try?

That indicates that power is supplied by your PC, the board draws too much current so your PC cuts the power, the PC applies the power again, cuts it again and so on; total of 8 times.

I'm not a Mac user but you should be able to find warnings/errors somewhere in the system logs.

Did you take the Nanos out of the conductive packaging? Did you remove protective foam? Are they laying on a conductive surface?

That does not mean anything to us an most of us will not start hunting or them on the web; in future please provide an URL.

Does the nano take a different amount of power from the PC than the Uno?

I am using a USB to USB C adapter, which I didn’t think would be relevant since I use the same one with my Uno and have no issues.

However if it is failing to regulate the power somehow, maybe it is.

A Nano might draw slightly less, not more.