New Pixhawk 2.1 , Solid Green LEDs around base. NoGo

I have a new out of box Cube. On power up with USB cable , The GREEN leds turn on solid, ( around the base joint between carrier and cube). No com port appears on PC. Will not connect for a firmware flash.
If I power up with a power loom and battery it does the same thing.
Any ideas?

Hi.I got the same problem as yours and I sent it back to reseller to change for new one.

Hi, Thanks very much for the reply.
I had another cube to get flying with that worked, but we just got a supplier reply that suggested trying another USB cable and returning it if that doesn’t work.
I’m pretty sure from memory that I have tried several cables.
I’ll double check it , and look to sending it back for a new one.

Thanks again.