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Arris SB8200 connection drops

New Poster

Arris SB8200 connection drops

I recently upgraded my plan from the 175mb to the 300mb internet. I went ahead and bought the Arriss SB8200 because I do eventually have plans on going to the 1gb plan. A couple days after purchasing the modem I would intermittently lose internet. I chalked it up to work in the area because my old modem dropped out once or twice right before I switched (taking note it hasn't dropped internet randomly in months).


It has been raining really bad recently and there's a box at the end of my driveway which contains the node to my house and my neighbors house. It constantly gets hit by cars because of it's location and I'm 99% sure the wiring is bad here.


Arris is telling me there are a lot of T3 errors which then results in a SYNC Timing Synchronization failure. So from ~9PM-9AM I have no internet. I have to manually reset the power to the modem only for it to drop out a few minutes later. This has been happening since Sunday (8/23) night. I switched my modem over to the new one on Friday (8/21).


So I'm sure most of the noise in my line is caused by this box at the end of my drive way that gets hit by cars. I had a tech come out and try to bury it some more into the ground and he ended up bending the wire into a hard L shape. This caused my internet and TV to drop in the house. He eventually undid his work and just put a stake in the ground to hold it upright more. I'm now assuming after all this rain the water is just sitting around the node, possibly causing the noise. I've read several posts online saying the SB8200 has a lot of T3/T4 issues when the day winds down and activity is a lot less.


I'm trying to decide if I need to switch back to my old modem until a person comes out and checks the node outside my house. If anyone has any ideas it would be greatly appreciated!


Maybe I don't have the most recent firmware version? Here are my stats:

Hardware Version6
Software Version



Downstream Bonded Channels
Channel IDLock StatusModulationFrequencyPowerSNR/MERCorrectedUncorrectables
5LockedQAM256507000000 Hz-6.5 dBmV33.4 dB00
1LockedQAM256477000000 Hz-5.4 dBmV41.1 dB00
2LockedQAM256483000000 Hz-5.3 dBmV41.2 dB00
3LockedQAM256489000000 Hz-5.4 dBmV32.6 dB00
4LockedQAM256495000000 Hz-6.1 dBmV36.4 dB00
6LockedQAM256513000000 Hz-6.9 dBmV35.7 dB00
7LockedQAM256519000000 Hz-7.4 dBmV40.7 dB00
8LockedQAM256525000000 Hz-7.7 dBmV40.7 dB00
9LockedQAM256531000000 Hz-8.7 dBmV28.8 dB70472111708528
10LockedQAM256537000000 Hz-9.5 dBmV28.9 dB784241788
11LockedQAM256543000000 Hz-9.9 dBmV31.4 dB121560
12LockedQAM256549000000 Hz-10.3 dBmV36.4 dB00
13LockedQAM256555000000 Hz-10.7 dBmV38.2 dB00
14LockedQAM256561000000 Hz-10.3 dBmV39.4 dB00
15LockedQAM256567000000 Hz-9.9 dBmV39.6 dB00
16LockedQAM256573000000 Hz-9.8 dBmV39.7 dB00
17LockedQAM256579000000 Hz-9.2 dBmV40.0 dB00
18LockedQAM256585000000 Hz-9.5 dBmV39.7 dB00
19LockedQAM256591000000 Hz-9.6 dBmV30.4 dB5216967389730
20LockedQAM256597000000 Hz-9.7 dBmV37.0 dB290
21LockedQAM256603000000 Hz-9.7 dBmV39.6 dB00
22LockedQAM256609000000 Hz-9.7 dBmV39.6 dB00
23LockedQAM256615000000 Hz-9.1 dBmV39.8 dB00
33LockedOther690000000 Hz-8.4 dBmV33.8 dB162341820
34Not LockedQAM2560 Hz0.0 dBmV41.1 dB00
35LockedQAM256453000000 Hz-5.3 dBmV40.9 dB00
36LockedQAM256459000000 Hz-5.3 dBmV41.1 dB00
37LockedQAM256465000000 Hz-5.5 dBmV41.1 dB00
38LockedQAM256471000000 Hz-5.5 dBmV41.7 dB00
39LockedQAM256429000000 Hz-4.0 dBmV41.5 dB00
40LockedQAM256435000000 Hz-4.1 dBmV41.4 dB00
41LockedQAM256441000000 Hz-4.7 dBmV41.3 dB00


Upstream Bonded Channels
ChannelChannel IDLock StatusUS Channel TypeFrequencyWidthPower
141LockedSC-QAM35600000 Hz6400000 Hz38.0 dBmV
242LockedSC-QAM29200000 Hz6400000 Hz38.0 dBmV
343LockedSC-QAM22800000 Hz6400000 Hz37.0 dBmV
444LockedSC-QAM16400000 Hz6400000 Hz37.0 dBmV




Re: Arris SB8200 connection drops

The downstream power is generally too low / weak (some are out of spec as are some of the SNR's). That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.


Some stuff that you can try. If none of the below applies, then you'll need a tech out to investigate / work on that tap / pedestal.

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.

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New Poster

Re: Arris SB8200 connection drops

I have 1 CommScope splitter that is 5-1002Mhz. The main line hits the splitter and 1 goes to the modem while the other goes to my HDHomeRun Prime.


I believe this splitter was supplied to me by Comcast when they initially connected my house back in 2014.


I checked the fittings and everything is tight and orderly. My house was built with a SCP panel so it houses all of my stuff in my closet. No other electronic shows any corrosion or other deterring effects.

New Poster

Re: Arris SB8200 connection drops

I just got off the phone with Comcast and was told that getting a tech out isn't doable because of COVID. The guy wasn't from the US so I'm not sure he fully understood my issue and just sent a "reset" to my SB8200.


I had asked him to change my modem back to my old one and then submit a ticket for a tech to come out but he did neither of those since he said the reset he sent to the 8200 "should fix my issue". I really don't want to wait until 9PM for my internet to go down for the fourth night in a row. I have security systems and other things that rely on my internet, let alone the fact that I'm paying for no internet.


I know this box outside is the point of fault as it has been in the past. What do I need to say or be able to call someone in the US to help me? Thanks.

Frequent Visitor

Re: Arris SB8200 connection drops

I am in exactly the same boat. My modem logs look very similar to yours, I also have the SB8200. I have literally been on chat with Xfinity since 4am this morning. They will send a signal and it makes things worse. Then I keep getting the run around about a tech coming out. I have spent 100+ bucks putting in all new cables. I have no splitters at all. I have done everything mentioned in this forum and I still cant get over 500 on a 1GB plan. I show them pics of speed tests and they still wont do anything. This is very frustrating. 

New Poster

Re: Arris SB8200 connection drops

Sorry I wanted to reply sooner but I was getting 401 errors when trying to login to this forum.


I finally got a rep who switched my modem back to my original one while I purchased a new one (Netgear CM1000v2). My network was just fine while I waited for the new modem to arrive. After I called back to get the Netgear activated and since my internet has been doing just fine in terms of not dropping out every night like it did with the Arris SB8200.


I believe though my stats look roughly the same (within a partially weak signal) due to the pedestal at the end of my driveway. Comcast says that the signal is fine and they can't send out a tech unless the system generates a ticket because of COVID. I guess I will have to wait for COVID to die down some before I can get someone out to check out the line again and hopefully replace the whole splitter out there as I know it is a contingent point of my network degredation.


Here are the stats with the Netgear:

<tabindex=-1>Downstream Bonded Channels (Partial Service)</tabindex=-1>
ChannelLock StatusModulationChannel IDFrequencyPowerSNR / MERUnerrored CodewordsCorrectable CodewordsUncorrectable Codewords
1LockedQAM25629651000000 Hz-11.3 dBmV39.6 dB169157307510
2LockedQAM2562483000000 Hz-7.1 dBmV41.1 dB1678390613520
3LockedQAM2563489000000 Hz-7.2 dBmV30.8 dB167838304305
4LockedQAM2564495000000 Hz-7.8 dBmV37.0 dB167842000340
5LockedQAM2565507000000 Hz-7.9 dBmV31.4 dB16784861613714
6LockedQAM2566513000000 Hz-8.1 dBmV38.1 dB167854235760
7LockedQAM2567519000000 Hz-8.3 dBmV40.9 dB167853522840
8LockedQAM2568525000000 Hz-8.3 dBmV41.0 dB167858686777
9LockedQAM2569531000000 Hz-9.2 dBmV30.5 dB1017807374988187397611
10LockedQAM25610537000000 Hz-9.8 dBmV29.9 dB4219090025208790811408339
11LockedQAM25611543000000 Hz-10.4 dBmV32.9 dB167846234420009
12LockedQAM25612549000000 Hz-11.0 dBmV37.9 dB1678965831280
13LockedQAM25613555000000 Hz-11.7 dBmV38.2 dB16789466115722
14LockedQAM25614561000000 Hz-11.7 dBmV39.6 dB167896329930
15LockedQAM25615567000000 Hz-11.8 dBmV39.6 dB167904586970
16LockedQAM25616573000000 Hz-12.2 dBmV39.3 dB1679086501410
17LockedQAM25617579000000 Hz-11.9 dBmV39.4 dB1679450921800
18LockedQAM25618585000000 Hz-12.5 dBmV39.2 dB1679557383180
19Not LockedUnknown00 Hz0.0 dBmV0.0 dB000
20LockedQAM25620597000000 Hz-12.8 dBmV35.1 dB167819425139787675
21LockedQAM25621603000000 Hz-12.8 dBmV38.9 dB1679646943030
22LockedQAM25622609000000 Hz-12.9 dBmV38.8 dB1679716083130
23LockedQAM25623615000000 Hz-12.2 dBmV39.1 dB1679744311933
24LockedQAM25624621000000 Hz-12.0 dBmV37.1 dB1679769651420
25LockedQAM25625627000000 Hz-11.9 dBmV37.2 dB1678183461604357349
26LockedQAM25626633000000 Hz-11.8 dBmV38.6 dB167989534750
27LockedQAM25627639000000 Hz-11.5 dBmV39.5 dB167989878540
28LockedQAM25628645000000 Hz-11.4 dBmV39.6 dB167995900400
29LockedQAM25630657000000 Hz-11.3 dBmV39.4 dB168006142660
30LockedQAM25631663000000 Hz-11.4 dBmV39.4 dB168002773640
31LockedQAM25632669000000 Hz-11.0 dBmV39.5 dB1679157084135552334
32Not LockedUnknown00 Hz0.0 dBmV0.0 dB000

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
ChannelLock StatusModulationChannel IDFrequencyPower
1LockedATDMA4135600000 Hz42.3 dBmV
2LockedATDMA4229200000 Hz42.0 dBmV
3LockedATDMA4322800000 Hz40.8 dBmV
4LockedATDMA4416400000 Hz40.3 dBmV
5Not LockedUnknown00 Hz0.0 dBmV
6Not LockedUnknown00 Hz0.0 dBmV
7Not LockedUnknown00 Hz0.0 dBmV
8Not LockedUnknown00 Hz0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
ChannelLock StatusModulation / Profile IDChannel IDFrequencyPowerSNR / MERActive Subcarrier Number RangeUnerrored CodewordsCorrectable CodewordsUncorrectable Codewords
1Locked0, 1, 2, 333690000000 Hz-10.5 dBmV32.8 dB1228 ~ 2867706075640670184990147
2Not Locked000 Hz-7.3 dBmV0.0 dB0 ~ 4095000

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
ChannelLock StatusModulation / Profile IDChannel IDFrequencyPower
1Not LockedUnknown00 Hz0 dBmV
2Not LockedUnknown00 Hz0 dBmV

Re: Arris SB8200 connection drops

Most of the downstream power levels are still poor / out of spec. Your new modem may be a bit more tolerant of less than stellar stats than was the previous one. This still should be addressed nevertheless. Good luck !

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!