Little to no internet access for almost a week

I've basically had no internet access since last Thursday. A few hours on Tuesday,  but nothing else. I'm assuming it's a problem with my router, but I'm not sure.

My router is a Netgear CG3000D. What I see on the lights on front is, the downstream light blinks then stays solid, then the upstream light blinks then stays solid, then the Internet light blinks quickly for a few seconds before all the lights turn off and the sequence starts again. When the connection has been successful in the past, the sequence is the same except the internet light starts blinking more slowly after a short time, then goes solid, with those three lights staying solid as long as my internet doesn't go down. 

What I see in the router's event log is an alternating sequence of "no ranging response received" and "unicast ranging received abort response".

Is this something that can be fixed remotely or by myself following simple instructions with no risk of damaging rented hardware? Is it a hardware problem that I need to bring it to a Cox Solutions Store to get it fixed or replaced? Is my only option to call a technician to observe my actual setup and find some way to reduce Electromagnetic interference? Those options are arranged in order of preference, but I really need stable internet by next week and I'd prefer to at least have it back to it's previous state of only going down for an hour rather than for days.