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scififan68

join:2010-10-02
Fremont, NE

Defective SB6141 Modem?

I bought my own SB6141 so that I could utilization channels better, but I noticed recently is that it would stop working about once a month. But It is not easy to determine the issue until yesterday it did it again and I rebooted both my WNDR3700 and SB6141 and internet came back on. I had really slow page loading(high pings) then all pages stopped loading entirely. Then today it just did it once more and rebooting the modem allowed me to get on the internet, so I'm now 99% sure it is indeed a bad modem or maybe a bad coaxial cable, which isn't very old. My modem seems to had 5000 correctable errors within 17hours. But I'd like to get a second opinion on the matter. Also my signal is well within range 3 dBmV / 45 dBmV and an SNR of 38 so its not that.



swintec
Premium,VIP
join:2003-12-19
Alfred, ME
kudos:5

Is it possible your router has gone bad? Another unit you have kicking around that you can try for a bit?
--
Usenet Block Accounts | Unlimited Accounts


scififan68

join:2010-10-02
Fremont, NE

It has been knocked around a few times by our cats, so it could be, but what is odd is that I lost internet so I rebooted the modem and the internet started working. Yesterday I rebooted the router first and it didn't come back on still, so I rebooted the modem then it started working fine after a few mins. Both times I coudl get into both the router and the modem, but the internet would not work. The top of the SB6141 feels very warm. There are no errors in the log other than it shows that I unplugged the modem to get internet to work, but it did show "SYNC Timing Synchronization failure" only once, last time I'd say about a month ago.



TransitMan
Premium,MVM
join:2000-09-05
Dayton, OH
kudos:1
Reviews:
·Time Warner Cable
reply to scififan68

Those 5000 correctables from the log is indicative of noise problems on the line, outside of the residence.
Contact TWC tech support and give them this information. They will be able to see your area to find out where the problem might be.
They may also do a truck-roll, just to make sure the drop from the pole to the house is OK.

Just because the cats knocked over the router does not make for a defective router. The problems lies elsewhere.



DrDrew
So that others may surf.
Premium
join:2009-01-28
SoCal
kudos:12

said by TransitMan:

Those 5000 correctables from the log is indicative of noise problems on the line, outside of the residence.
Contact TWC tech support and give them this information.

5000 correctables can be a drop in the bucket.

The number of correctables/uncorrectables should ALWAYS be compared against the number of unerrored or total codewords.

Often you'll find the percentage of correctables/uncorrectables to be some minuscule percentage of the total codewords received, in which case it's nothing to worry about.
--
If it's important, back it up... twice. Even 99.999% availability isn't enough sometimes.


Buclic

@rr.com
reply to scififan68

Do you have to remove a router from the path before logging into the modem?

And secondly, where is the poster seeing a correctable/uncorrectable errors log? The last time I looked in my modem it had a log, but it was not very detailed and didn't have that kind of information, but I think I went through the router.. It mostly showed boot-up info.
Thanks.


scififan68

join:2010-10-02
Fremont, NE
reply to scififan68

I also have an Arris TM602G which I could switch over with a call to TWC. I will also revert to stock firmware on my WND3700 once everyone is off the internet. We do get sporadic drops from wireless with this router, but wired is rock solid, the wireless drops could be a firmware issue. @DrDrew I was thinking the modem was causing correctable to increase, but that probably isn't right.
@Buclic On the SB6141 you can see all the signal stats including correctable and uncorrectable errors as well as signal stats on the same page.



DrDrew
So that others may surf.
Premium
join:2009-01-28
SoCal
kudos:12

Just to give an example of my earlier post:
5943703026+419+1739=5943705184=100% of codewords
1739 uncorrectable codewords= 0.000029% of codewords or 1 uncorrectable in 3.4 million codewords.

The uncorrectable codewords are not a problem.
--
If it's important, back it up... twice. Even 99.999% availability isn't enough sometimes.


scififan68

join:2010-10-02
Fremont, NE

@Dr drew Yeah I know which is why I am focusing on my modem and router.


scififan68

join:2010-10-02
Fremont, NE

While I was sleeping it seems that my modem switched channels from 741MHz and 36MHz to 735MHz and 32MHz and when I checked the logs I got one 'T4 timeout' and two 'SYNC Timing Synchronization failure - Loss of Sync' errors. Clearly something is very wrong, I'm going to to have Tier 3 check on my arris modem for the same errors since I cannot get into it myself. Here is a picture:



motorola870

join:2008-12-07
Arlington, TX
kudos:3

said by scififan68:

While I was sleeping it seems that my modem switched channels from 741MHz and 36MHz to 735MHz and 32MHz and when I checked the logs I got one 'T4 timeout' and two 'SYNC Timing Synchronization failure - Loss of Sync' errors. Clearly something is very wrong, I'm going to to have Tier 3 check on my arris modem for the same errors since I cannot get into it myself. Here is a picture:

no those T4 timeouts and SYNC Timing errors are normal when your modem switches channels on the downstream or upstream. Likely your area is using loadbalancing and your modem got reset overnight due to maintenance and the modem rebooted into 735MHz downstream and 32MHz upstream. You might have had DOCSIS 3.0 work going on at that time of night last night as TWC is trying to get almost 100% coverage of DOCSIS 3.0 by the end of the year.

scififan68

join:2010-10-02
Fremont, NE

1 edit

Ah, well there is nothing about Fremont, or even Lincoln on the network status page, but they did finally upgrade to the new navigator last week, and I was told by the office sometime in September for Docsis 3, but I won't believe it until I see it. EDIT: Also both modems went out, seems to be something with TWC itself.



motorola870

join:2008-12-07
Arlington, TX
kudos:3

said by scififan68:

Ah, well there is nothing about Fremont, or even Lincoln on the network status page, but they did finally upgrade to the new navigator last week, and I was told by the office sometime in September for Docsis 3, but I won't believe it until I see it. EDIT: Also both modems went out, seems to be something with TWC itself.

I am pretty sure if both of your modems went out either the CMTS was being worked on or a new firmware was pushed out but since one modem is a motorola and the other an arris I am going to bet CMTS maintenance.

scififan68

join:2010-10-02
Fremont, NE

2 edits

Well I got another "SYNC Timing Synchronization failure - Loss of Sync" on Sep 20 2012 15:40:09.



It now shows 0 dBmV(was 2to4dbmv before) even after rebooting, anyone ever seen this? I've read that they could have turned off the measurement of the downstream signal level.
EDIT 9-22: seems to be all modems in my city, not just mine, hmmm it looks like my signal really is 0 now, interesting, but it did move up to 1dBmV.

scififan68

join:2010-10-02
Fremont, NE

I wonder if my issues with my SB6141 are due to noise, I woke up today and checked my arris mta and my snr is 27, I've checked all wiring on the inside and no problems there and even hooked up my now unused SB6141 to a different port on the splitter and yeah the snr is still 27! I also had 13% correctables, I checked that with tier 3 today. I find it funny how my signal is 1dBmV and 43dBmV with an SNR of 27, while the only noticeable issue is speedtests come out lower, TWC is coming out Monday to fix it.


scififan68

join:2010-10-02
Fremont, NE

2 edits
reply to scififan68

I bought a second SB6141 to try out and I just had a T3 timeout with jump in uncorrectable errors by millions. "Nov 23 2012 04:09:27 3-Critical R02.0 No Ranging Response received - T3 time-out"
This isn't the first error I've had with this modem, I did have a drop in the internet with these errors:
"Jan 01 1970 00:00:14 6-Notice Cable Modem Reboot due to T4 timeout
Nov 14 2012 21:58:45 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted
Nov 14 2012 21:58:45 3-Critical R03.0 Ranging Request Retries exhausted
Nov 14 2012 21:58:43 3-Critical R02.0 No Ranging Response received - T3 time-out"
I've looked up those and I believe it was noise on the upstream that caused the drop. I called tier 3 about that and they said my signal is fine, but they saw a bit of a drop, and to call them if I have any other issues. That was 9 days ago, and what I'm wondering what is causing these big jumps in errors, enough to cause a T3 timeout. My signal is fine and doesn't move around more than 3db. Should I be worried or am I worrying too much?
Edit: I know that the % of errors vs total codewords is pretty small, so I shouldn't worry at all? T3's only cause drops when you have many of them, but I'm trying to determine if I should return this modem or keep it.




JohnnyG101
Mafiaoso
Premium
join:2000-12-25
Charlotte, NC
Reviews:
·Time Warner Cable
reply to DrDrew

said by DrDrew:

Just to give an example of my earlier post:
5943703026+419+1739=5943705184=100% of codewords
1739 uncorrectable codewords= 0.000029% of codewords or 1 uncorrectable in 3.4 million codewords.

The uncorrectable codewords are not a problem.

thanks for this explaination/example....always wondered about this.
--
Driving with 2 feet since 1999

Emiya

join:2006-03-30
Southington, OH
reply to scififan68

I just activated a new SB6141 and am getting T3 timouts on any upload over about 2mbps for more than a few minutes. I've spent a few hours on the phone with L3 and finally managed to convince one that there was an issue. I only get 1 T3 timeout in my logs per disconnect. The modem recovers in a minute.

Signal levels are fine. All 4 bonded downstream channels show a snr of 36-37dB, power is 0-1dBmV. My upstream is 48dBmV. There is very little fluctuation in the numbers at all. None of the techs I've talked to have seen anything at all wrong signal-wise but I have a truck roll scheduled for Sunday morning.


scififan68

join:2010-10-02
Fremont, NE

I haven't any disconnects since 9 days ago, but the correctable and uncorrectable errors are climbing, a few channels have over a million more errors. Whats funny is that my internet speeds are fine and nothing disconnecting right now, but you never know.


Fleeced

join:2012-10-06
kudos:2
reply to scififan68

Just an FYI: your downstream power is supposed to be within the range of -10db and 10db. 0 is "perfect" for downstream strength.


ltm320

join:2002-02-24
Milwaukee, WI
reply to scififan68

I am having some similar issues. I have RR .. had the SB51xx modem and purchased a SB6141, got it 4 days ago.

While my SB51xx was rock solid for years, the SB6141 is terrible and is rebooting itself every 1-3 hours or so. The signal levels all seem fine, according to Motorola's specs. -- Plus, hey. the old cable modem was perfect for years, although it was docsis 2, and the sb6141 is 3.

I did an online chat with RR's tech support .. the guy said "you have old firmware, go to Moto and install newer." I didn't think that was right, since Moto doesn't have firmware on their site and believed firmware needed to be pushed by the ISP. He didn't believe me. I verified this with Moto, naturally.

Question: Someone with a SB6141, can you tell me what your firmware is? Here's my info from »192.168.100.1/cmHelp.htm

Model Name: SB6141
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.3-SCM03-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.
Hardware Version: 7.0

Firmware Build Time: Aug 18 2011 10:27:53

The bigger question is .. if I get them to push a new firmware .. will that even help? It's really maddening how often it is rebooting .. I think it's the log entry "No Ranging Response received - T3 time-out" that puts it into a death spiral.


Emiya

join:2006-03-30
Southington, OH

said by ltm320:

I am having some similar issues. I have RR .. had the SB51xx modem and purchased a SB6141, got it 4 days ago.

While my SB51xx was rock solid for years, the SB6141 is terrible and is rebooting itself every 1-3 hours or so. The signal levels all seem fine, according to Motorola's specs. -- Plus, hey. the old cable modem was perfect for years, although it was docsis 2, and the sb6141 is 3.

I did an online chat with RR's tech support .. the guy said "you have old firmware, go to Moto and install newer." I didn't think that was right, since Moto doesn't have firmware on their site and believed firmware needed to be pushed by the ISP. He didn't believe me. I verified this with Moto, naturally.

Question: Someone with a SB6141, can you tell me what your firmware is? Here's my info from »192.168.100.1/cmHelp.htm

Model Name: SB6141
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.3-SCM03-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.
Hardware Version: 7.0

Firmware Build Time: Aug 18 2011 10:27:53

The bigger question is .. if I get them to push a new firmware .. will that even help? It's really maddening how often it is rebooting .. I think it's the log entry "No Ranging Response received - T3 time-out" that puts it into a death spiral.

Same firmware, similar issue although mine is only with heavy upload. Second tech that came out found a noise issue on the main line down the road on Thursday. Linemen came out on Friday and did some work but the issue still persists.

I've gotten the same runaround with firmware as well. They swear they cannot push firmware to a customer owned modem.


swintec
Premium,VIP
join:2003-12-19
Alfred, ME
kudos:5
Reviews:
·Time Warner Cable
·VoicePulse
·Sprint Mobile Br..
·RapidVPS
reply to ltm320

I have that same firmware and it has been working perfect since March or April when I activated it. Our of curiosity, does your modem show any upstream bonding?

One of the modem errors (possibly the t3) causes the modem to reboot after so many of them in a row. Someone better versed in the errors can confirm.
--
Usenet Block Accounts | Unlimited Accounts


scififan68

join:2010-10-02
Fremont, NE
reply to scififan68

You know whats ironic, that I bought a second SB6141 and it turned out to be defective. I do recall getting "No Ranging Response received - T3 time-out" among other errors. It took 11 days before it started to really malfunction, but when it started, it worked for a min then reboot and over again. Good thing I had my first SB6141 which has been working great for the last two days with Extreme! »speedtest.net/result/2346731761.png
Seems these modems may have many duds, but I could just be unlucky.


ltm320

join:2002-02-24
Milwaukee, WI
reply to swintec

said by swintec:

I have that same firmware and it has been working perfect since March or April when I activated it. Our of curiosity, does your modem show any upstream bonding?

Looking at the admin menus, I think the answer to your question is no .. there's only one upstream channel bonded (#4) .. where there are 4 channels in the downstream "bonding" table.

Got TWC coming out in a few hours. Hope they find something, or I'll need to return this modem, get a new one.

Fleeced

join:2012-10-06
kudos:2
reply to Emiya

CSRs do not have the ability to push firmware to an internet modem. This is an automated process they have no control over. The only time they can push firmware is for the phones.



hobgoblin
Sortof Agoblin
Premium
join:2001-11-25
Orchard Park, NY
kudos:9

" The only time they can push firmware is for the phones. "

A CSR can not push firmware period.

Hob
--
"A foolish consistency is the hobgoblin of little minds."
- Ralph Waldo Emerson


scififan68

join:2010-10-02
Fremont, NE

1 edit

Well more random uncorrectable and correctable jumps, seems the transmit went down by 1dB to 42dBmV its usually 43-44, it is very cold today as well, but I keep getting sporadic jumps in codewords by at least a million, no packet loss that I know of and it causes a single T3. My modem has only been on for 2 days. TV seems to have random correctable and uncorrectable error jumps but I can't point my finger at when it happens it just does. A tier 3 agent actually said my signal was 10dBmV and 31dBmV with a lot of errors but my modem showed 6 and 43 so I had nothing done about it. I may try switching back to the cable I made, but I don't think it should be doing this. I think that something is wrong outside of my house.
P.s. »dl.dropbox.com/u/38348368/logful···rors.PNG I woke up to a log full of these errors a few days ago which forced my modem to reboot.



kilrathi
Premium
join:2005-04-22
Rockaway Park, NY
reply to scififan68

T3 time out errors mean you have noise on the upstream, it can be as simple as someone in he area having illegal cable hooked up to a bad device and its causing noise or bad tap. Further since your node uses upstream modulation of 64QAM u have less room for noise, there is really no need for 64QAM from cable company standpoint on upstream anyways for the packages they offer, it only leads to problems. But yes you most likely have upstream problems, however those high uncorrrectable numbers are on downstream so I wouldnt rule out noise thats affecting both downstream and upstream.


scififan68

join:2010-10-02
Fremont, NE

said by kilrathi:

T3 time out errors mean you have noise on the upstream, it can be as simple as someone in he area having illegal cable hooked up to a bad device and its causing noise or bad tap. Further since your node uses upstream modulation of 64QAM u have less room for noise, there is really no need for 64QAM from cable company standpoint on upstream anyways for the packages they offer, it only leads to problems. But yes you most likely have upstream problems, however those high uncorrrectable numbers are on downstream so I wouldnt rule out noise thats affecting both downstream and upstream.

I actually bought a second SB6141 because my first was acting up a bit, but the replacement did once disconnect which I believed was due to upstream noise, but I'm never awake to see it happen, so all I get to see is the error log. I returned my new one but I doubt it was defective, I know that modem kept looping and wouldn't even stay synced for more than a minute and I wonder if noise was causing that? If you look through my thread you will see the errors that piled up on that one as well, seems to be go from lowest to highest, with 723MHz having least and 741MHz having the most. Which makes me think that is coming from a higher frequency?

The last time a tech came out my signal has an MER of 40dB, but that was pre-docsis 3 it could have dropped. I've always got some correctable and uncorrectable errors, but I don't recall millions of them in a burst then stop for a few days or 5 days I haven't found a pattern other then it seems to happen on Saturday night to Sunday morning, maybe? The CMTS swap from Cisco to Arris could have made any minor issue worse that or Docsis 3 is more prone to the noise. Before I call I'm going to replace a cable, but if it still does that, I'm not really sure how I'm going to get them out, I always thought I had didn't have enough evidence to get it looked at, we had a new drop installed in April and I've tried swapping modems and even I recall my Arris MTA getting a random T3 but it didn't cause any internet issues so I wasn't worried, but the last time I talked to Tier 3 they said my signal wasn't optimal either so maybe it won't be so hard to get this looked at. Also my signal is sitting at 6dBmV and 41dBmV while its 7F outside.