Please: I need help with intermittent connection errors

[Clump]

I have an Arris SB6183 and have a very similar issue to the OP - Lots of uncorretables and Maintenance Ranging errors. My log looks very similar.

Some background:

I bought this modem in February to replace 1 that gave up. We had months straight of up time.

When the weather got hot we started having issues. Xfinity replaced some pedestal equipment and it got better, but with occasional disconnects. I switched to a leased modem to eliminate the SB6183. It was solid for a while, but recently experienced several disconnects a day.

Switched back to SB6183 a couple of days ago. Uptime is never more than a couple of hours (per modem status field), although neither of us have seen any real interruption.

[EG]

What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

[Clump]

Here they are. This afternoon it lost connection for a while.

[EG]

The upstream power is too high / out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

[Clump]

Thanks! I really appreciate the help.

I exercised all of the connections. There is no splitter, but there is a connector. After taking all the connections apart and reassembling them tight the upstream power levels are unchanged.

FWIW I have a 10db pad right at the modem, which was suggested here some time ago and brought my downstream power levels into spec.

[EG]

Yes but it works the opposite for the upstream power. It makes it 10dB higher. It's always a balancing act. Take it out and see what happens. If you still need the downstream power to be lowered, you can use a forward path only attenuator. They don't affect the upstream power.

With it out you should wind up at about +6 - +7 which is o/k.

[Clump]

Here it is with the pad out

[Clump]

Let's try that again.

Here it is with the pad out

[EG]

The upstream is now good. The downstream is strong but is in spec. Bottom line. Live with it a while and see what happens.

[Clump]

It was off line when I got up this morning. I see the SB6183 is no longer on the approved equipment list. Would a new modem help? We have a relatively low speed plan, below 100mbps.

[EG]

It is still on the approved list: https://mydeviceinfo.xfinity.com/device/arris-sb6183-417

I'm using one as we speak. You could try a swap. Try renting one of their modems for a month as a test. Some modems are more tolerant of less than stellar line conditions than are others. You could also get a tech out to investigate Good luck with it !

[Clump]

Thanks!

I was looking at higher speeds, but found my modem in the list after posting. Tried a rental modem for a few months and while it seemed better at first had the same disconnect issues, prompting going back to my owned modem. 

When I get home tonight I'll exercise the outdoor connections as a last try before scheduling a tech visit.

[Clump]

We had a really bad day yesterday. Internet was mostly down all day. Mu GF works at home and it's impossible for her to do anything without internet access. I had her put the pad back in, which made no difference at all. I ordered a Netgear CM1200 thinking (hoping) my SB6183 is most of the problem. Although we won't use the speed capability figured having the latest and greatest wouldn't hurt. 1 day Prime shipping. I would have bought it locally, but it was $50 more.

When I got home I dis/re- assembled the outdoor cable connections. Other than a very large spider inside the box everything looked good and they were very tight. We have had uninterrupted service ever since. The levels are the same as before. I looked this morning before I went to wrok and it had been up nearly 12 hours, with 0 uncorrectables. Really should have done the outdoor piece when I went through the indoor. It probably would have saved a bunch of grief. 

We'll see how the day goes. Her VPN is very sensitive to errors. If it's reliable today I need to decide what to do with the new modem.

Thanks again EG for all of your help!

[EG]

Good luck ! Post back with how things turn out.

[Clump]

Yesterday morning it went down around 9:30 and stayed down until about noon. I had her take the pad back out, but don't think that made any difference.

When i got home I swapped out to the new Netgear CM1200 cable modem. When I called Xfinity  I got a slow tech, but he finally got it provisioned. Power and SNR are very similar to the old SB6183., both up and down. 

It's been up now for nearly 24 hours with no interruptions! If things contiinue like this it was worth the money.

[Clump]

We're now over 4 days uninterrupted with the new modem! It was expensive, but seems to have been worth it.

[EG]

Hope things hold up for you !