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atarnakh

join:2013-07-07
Cleveland, OH

Modem (SB5100) frequent disconnects - is it going bad?

TL;DR version: if the modem (a Surfboard SB5100) only seems to work reliably while being air conditioned close by does that signify that it's gone bad?

Full version: I'm on standard internet and when my connection is up it's very fast. But for several months now it's been extremely unrealiable. Mostly during the day it disconnects up to several times an hour and reconnects after 1-3 minutes.

A tech came out, said I had good signal at the modem (which I knew). Then we wen't to my apt. building's attic (50 unit building - mostly AT&T U-verse users by now though) and he claimed the connection up there was a bit loose (I don't know whether to believe this or not but it's possible) and thought that'd be the fix, since signal up there was good too. Our wiring is very messy and undoubtedly old, but good levels are good levels.

But his "fix" didn't help anything. I'm still getting the disconnects.

However I remembered that a few weeks ago things were surprisingly stable when I had the A/C on. So today I've tried it again. And sure enough, after about 6 hours of use, virtually no error messages in the log (T3/T4/DHCP error triad usually) or simultaneous disconnects in my "real world" use yet. I want to repeat the experiment on other hot nights though to help be more certain.

The fact is that this modem is the better part of a decade old. I swapped it back in when TWC began charging their lease fee. I knew it was not on the approved list anymore but decided to try, and the provisioning people didn't care. Since it's 99% similar to the 5101, I figured no issue. But it was in storage for a long time and since the spring and increased heat and humidity, the problem has worsened.

I didn't want to risk buying a newer/more expensive modem but the experiment to me shows a strong clue that the modem may be at fault after all and that its guts (it's very exposed with a lot bigger vents than many of the newer models) have become oversensitive to environmental conditions.

I'm thinking it may be time for a Zoom 5341J Docsis 3.0. What do the experts here think?

Thanks.

scififan68

join:2010-10-02
Fremont, NE
I've had a friend with a SB5101 modem and it started to do that, once he got it swapped with a Cisco modem all the issues went away, so it seems that is what those modems do when they go bad. It could also be overheating, but that usually that just means its going bad as well.

Now I had bad luck with the Zoom 5341J, but that turned out to be an electrical outlet wired backwards causing havoc on our dvr and cable modem. High chances that I'd now not have any issues with the 5341J. The SB6141 is also a good choice if its not much more than the Zoom.

atarnakh

join:2013-07-07
Cleveland, OH
said by scififan68:

I've had a friend with a SB5101 modem and it started to do that, once he got it swapped with a Cisco modem all the issues went away, so it seems that is what those modems do when they go bad. It could also be overheating, but that usually that just means its going bad as well.

Now I had bad luck with the Zoom 5341J, but that turned out to be an electrical outlet wired backwards causing havoc on our dvr and cable modem. High chances that I'd now not have any issues with the 5341J. The SB6141 is also a good choice if its not much more than the Zoom.

Thanks. Yeah, this modem has always been "chatty" (I think all the Motos have that rep) but these errors coupled with the disconnects are another thing entirely. The reason I'm leaning toward the Zoom is that all the Motos have gained the rep throughout the years of being extremely finicky with their tolerable levels especially the upstream, and there are reports out there of people having much more solid connexs with the Zooms even with borderline signals.

I've almost never seen my upstream levels above 49 but I think that's the culprit along with the modem's "rust" (with the air cooling making that almost vanish during these times I've had it going). If anyone can argue the other side about why I'm wrong or talk about your own experiences, please do.


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

1 recommendation

reply to atarnakh
You have a ten year old non approved modem.
Swap it.

Personally I would always take a Motorola modem over a Zoom.

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

atarnakh

join:2013-07-07
Cleveland, OH
said by hobgoblin:

You have a ten year old non approved modem.
Swap it.

Personally I would always take a Motorola modem over a Zoom.

Hob

Mind saying why from your pro level view? There are many more reports of connection stability issues out there with Moto Surfboards, although there are many more of them out there period, plus the ones I mentioned where someone stopped their problems after trading a SB for a Zoom.

scififan68

join:2010-10-02
Fremont, NE
reply to atarnakh
If you have some underlying issues, then swapping it won't fix it, but its sure worth a try and I hope that your modem is the only issue, if not it could take a while to track down the root cause. I just recently fixed the problems we were having with our cable service and it took me months to figure out and it was all in this house. Heck there was still a minor issue after we fixed the big issue I previously mentioned. It's truly amazing what miswired electrical outlets and people plugging a tv and game console into different circuits can do. Also if you want you can post your signals here and if your upstream power level is going up randomly to 50dBmV+ then that could cause disconnects too.

Edit: that depends on the area really, some people said the SB6141 worked better while others said the 5341J worked better for them.


hobgoblin
Sortof Agoblin
Premium
join:2001-11-25
Orchard Park, NY
kudos:11
reply to atarnakh
I have way more experience over the last 14 years supporting Moto modems. Despite the threads about firmware and stability in here I believe the vast majority are signal related.
Sure you can find one or two threads where someone claims a XXXX modem solved the issue but without really troubleshooting I am skeptical.

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

atarnakh

join:2013-07-07
Cleveland, OH
reply to scififan68
said by scififan68:

If you have some underlying issues, then swapping it won't fix it, but its sure worth a try and I hope that your modem is the only issue, if not it could take a while to track down the root cause. I just recently fixed the problems we were having with our cable service and it took me months to figure out and it was all in this house. Heck there was still a minor issue after we fixed the big issue I previously mentioned. It's truly amazing what miswired electrical outlets and people plugging a tv and game console into different circuits can do. Also if you want you can post your signals here and if your upstream power level is going up randomly to 50dBmV+ then that could cause disconnects too.

Edit: that depends on the area really, some people said the SB6141 worked better while others said the 5341J worked better for them.

Yes, I've gone half-mad trying to research what the errors meant, plugging the modem directly into the mains, repositioning it, the router, etc., and right now I hope I'm not just grasping at straws. If it's a wiring issue with this building I may as well give up because it'd be extremely complex to fix (apartment bldg. issues etc. not to mention getting the work done with TWC)

But if the modem is acting much more stable when cooled and dehumidified, doesn't that point directly to a problem with it?

My signal levels have never looked bad, or if they go bad, it happens so fast it's impossible to witness or is just borderline bad when interacting with my modem.


DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:16
Although it's probably the modem, check the power pack rating to make sure it's supplying the voltage and amperage required by the modem. If the voltage or amperage is low the modem will have trouble

atarnakh

join:2013-07-07
Cleveland, OH
reply to atarnakh
It's definitely the original power supply with a huge brick that gets noticeably warm (and I think it's working fine although I have no way to test). If I'm going to need a new one, may as well spend more and get a modem with it.


hobgoblin
Sortof Agoblin
Premium
join:2001-11-25
Orchard Park, NY
kudos:11
reply to DrDrew
said by DrDrew:

Although it's probably the modem, check the power pack rating to make sure it's supplying the voltage and amperage required by the modem. If the voltage or amperage is low the modem will have trouble

That's a good call Dr.
From a customer care point of view, the fact that the modem is NOT on the approved list could be an issue if this is called in for support.

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

atarnakh

join:2013-07-07
Cleveland, OH
reply to atarnakh
Experiment is conclusive enough for me and is ending; picking up new Zoom modem tomorrow.

All through the morning and most of the afternoon, the SB5100 log was recording the usual pattern or disconnects up to 3-4 times an hour. This is when the room it's in was most hot and humid.

As soon as I came home I started the air conditioner. The errors diminished and then stopped altogether. I've been streaming audio and video with no issues or drops for several hours.

So the Zoom 5341J is my choice and even though I'm going to pay a somewhat elevated price, at least I can return it if I need to. I'll try it for some time and report back here about what the result is. If I reply soon it could be because it made no difference and it went back to the store. If it proves reliable, I'll wait to post again so I can try and get a sense of how it performs.

atarnakh

join:2013-07-07
Cleveland, OH
Update: Zoom modem is fine, although I find its paranoia about secure logins to its info pages and "secret" log page at »192.168.100.1/RgEventLog.asp ridiculous (and the truncated log lines are not a good design). Certainly I see no other obvious reason why someone should prefer the apples-to-apples compared but often much more expensive Moto 6141.

Unfortunately as some before have guessed, the underlying issue is very much still there. So another tech is coming out, this time a "Lead Tech" and hopefully they can do something. I'm not too hopeful due to the circumstances in my building, but it's the right thing to have done.

atarnakh

join:2013-07-07
Cleveland, OH
reply to atarnakh
In case anyone was wondering, this got fixed by a wire replacement. Took about 5 support calls and 3 visits (the 3rd was the cable install contractor) but ever since, no issues. Helps explain why the problem got worse when the weather turned hot and moist. At the end my modem would lose sync for sometimes hours at a time and the AC trick wouldn't work either. Well, at least I got a supported modem now too.