Factory Resetting of Hub3

Hi

I have just swapped out my hub3 and successfully installed a hub5. 

Because I was concerned I might have issues, I deliberately did not factory reset my hub3 before disconnecting, just in case I had problems with the hub5 install and needed to roll back.

I have since powered up my old hub3 and without connecting it back up have simply pressed the reset button for 30 secs. It then appeared to go through a restart and what could be a reset sequence but instead of eventually showing a solid white light (which I’ve read elsewhere is what happens at the end of the reset) the green WiFi light and light at bottom flash green…. I left it for over an hour and it continues to flash green - not a solid white light.

Presumeably it’s flashing green because it can’t find any network (because I’ve not connected it back up).

My question is: How can I be sure the factory reset has been successful? I don’t want to send it back to Virgin before I’ve removed my personal settings/device connection details etc…

I’ve not attempted swapping it back in as I don’t want to mess up my hub5 activation in any way.

Thanks in advance for any info you can give.