Thanks to all.
I am trying to go from an SB6141 to an SB6183. The 6183 ran fine for about three months and then would no longer train up, and I was getting a specific LED blink pattern on the front panel. I called Arris (seriously the most badass tech support I've ever received) and explained what was going on. I told the guy that I was a network engineer in a former life and he immediately dispensed with the "power your router on and off" stuff and started getting into the weeds with me.
He explained that the 6183, with its ability to train up and bond more channels, was more sensitive to channel interference and interference on the line that would lead to channels not bonding. Thus, the 6141, being less sensitive, could train up, but the 83 could not. My guess is that, in the three months that the 83 was running, something between Cox and my wall jack deteriorated such that, when we checked it on the 41 (the 83 may have suffered a firmware corruption when Cox pushed an update and I could no longer log into it, it wouldn't fully boot), my signal levels are barely at acceptable levels, even for the more forgiving 6141.
So Arris sent a replacement 83 and I called Cox to provision it, the new bridge never came up and I reverted back to my 41. The Cox gal was a sweetheart but clearly had no idea what was going on beyond taking my SN and MAC address and adding it to their database. I told her I'd check my schedule and see about getting a tech out to test the line when I have some days off coming.
Problem is, if I call Cox now, I am going to jump through a ton of hoops trying to explain what is going on, which I suppose is an inevitability. In addition, my network is complex -- but not the part for which Cox is responsible. The last Cox guy that came out (to initially set up service when we moved in, we had some issues because DirecTV cable was in the wall and we couldn't get Cox's service over it) freaked out when he saw firewalls, switches, access points, servers, cables, etc in my network cabinet. I tried to explain to him that his job was to get the cable modem working, AND THAT'S IT, and that I would take care of the rest. I hooked a single laptop up to the modem with a perpetual ping running just to satisfy him, bypassing my network. He seemed perturbed that I wasn't renting a modem and kept suggesting that that's what I needed to fix my issue.
So I'm trying to figure out if there are ways I can test some of this stuff myself, without violating Cox's policy by going into their curbside box myself (not something I am prepared to do).
I just don't want to have to tear everything apart to give a tech access to the wall jack (of course its behind a huge entertainment center filled with network equipment) only to have him spend four hours trying various splitters, filters, boosters, running new lines, etc, and then being satisfied if the modem comes up with only a handful of channels, not max speed, etc. "Well at least you have service, bye." That's happened before.
The fact that the 41 will train but the 83 will not is, in the opinion of the Arris tech, a pretty clear indication that the line itself needs some work. Maybe I can push for Cox to come out and test the line at the curb, to eliminate another variable, and deal with the home's wiring on my own?
Then again in the eight years I've had Cox service, I've had ONE tech show up who actually drew a paycheck from Cox, the rest were all contractors with magnetic signs on POVs. Not exactly confidence-inspiring.