Also, to add to it, the reset button isn't doing anything, held for 3-4 seconds or 10+, nothing happens. Neither did unplugging for 10 mins.

I have exactly the same issue.

I moved my modem slightly last night. Now it cycles solid amber, then flashes write, then off.

These ‘error codes’ don’t exist.

Resetting the device (pin for 4-5 seconds, or 10, or 30) does nothing. When its powered back on, the same light stays on. There is no reboot sequence.

I contacted Cox and they could not ‘see’ the modem. 

Guess I’m having an expensive trip to Bestbuy, and if this is the Arris modem after only a year, I’ll certainly never be buying one of these again. I can’t wait for a warranty replacement as I have no internet in the house apart from my phone.

After reset, if the problem persists, I suggest visiting www.arris.com/consumersupport for further assistance.