on September 23, 2013
Hi everybody, when I first bought the SBG6580 I was wary of the bad reviews and the disconnection problems, and I felt horrible when these issues started appearing in my SBG. Having solved the issue 2 weeks ago I would like to share it with as many people as I can to prevent this from happening to anyone else. The review I am about to write will cover the problem I encountered and the solution in a short and long format, and will be accompanied by photos. So let's begin-
*Short Version Guide:*
Go to 192.168.0.1, type in the username- admin and the password- motorola and look at the page that first appears (should be the Connection page). There should be three tables, look at the second one. Locate the Power column. If your power levels are negative, or if they're not within the range of -8dBmV and +8dBmV (meaning they are 9 or 10, or -9 or -10), you might have a problem. Now look at the third table and locate the power column. If your power levels are higher than 50dBmV, you might have a problem.
If it's not working well (meaning it works, but keeps disconnecting), it might look something like this- [Picture uploaded to costumer photos]
First thing you *should* do, although optional, is call Motorola support line. I've found them to have a great support line, and they'd be able to pinpoint the problem for you- their number is 1877-466-8646.
What they would probably tell you to do, and what you can do anyway if you don't want to call them, is to call your cable company support line. What you need is a technician to come over to your house and check all of your cable lines, to try and see why the power levels are bad, and the replace the cable or instrument that is malfunctioning (most likely not your modem, don't worry). The best way to get that is to call them up, be nice, go through all the hoops and all the attempts they try to restore your connection (if they manage to restore it, wait until it stops working again, call them again, and tell them it doesn't work and that you need a technician), and then eventually tell them that you need a technician because you called Motorola support and they said you have a problem with your power levels.
Usually that would do it. Don't be afraid to talk to the technician, show him the problem, but also listen to the tech and understand what they're saying.
Hopefully they'd get it right on the first visit, if not, do not despair, call them again.
I hope that helps anyone who's had the same issue as I did.
After fixing this issue my modem works great, the wifi extends throughout the whole house (2000sqft, cast walls mostly), and all channels are locked.
Good luck! Check out the extended guide below.
*Long Guide Version:*
*What causes the problem*
So let's get to the heart of the matter- Power levels.
Power levels are the strength of signal that your modem is receiving and sending through the cable connection. The SBG 6580 can handle power levels ranging from -15dBmV to +15dBmV for the download stream, and up to 55dBmV for the upstream (Not so sure about the negative upstream levels). That's all in theory though, because the actual OPTIMAL range is between -8dBmV to 8dBmV for the downstream, and up to about 52dBmV for the up stream. This doesn't necessarily mean that the Modem is crap because it can't handle higher (or lower) power levels, because it seems (after talking to TWC technicians) that these levels are also the cable companies' maximum and minimum power levels. So if you're exceeding these levels, there's a good chance your cable company is doing something wrong.
What are these power levels? In short, and to my completely ignorant understanding, they're the strength of the of the signal coming from through the cable from the cable company. This strength goes down as you move further away from the main line, or the place where they transmit the signal from. So basically the longer the wire is connecting your house to the "tap" (where the signal comes from)- the worse your power levels should be. The longer the cable going around your house- the worse your power levels should be. If it's an old cable, or the "tap" is malfunctioning- you're going to see bad power levels. (I say worse and bad instead of lower and low because I really have no idea how these things can work on a *negative* value, and how any of this works).
*Diagnosing the problem*
But let's not dwell on the technical mumbo jumbo and move on to *How to diagnose your problem, and how to solve it*-
The first thing we need to do is connect to our SBG6580 and get a reading of those power levels. The way to do that could not be easier- just type 192.168.1.1 in your browser address line (yes, it's a weird address, but it'll work). You'll be asked for a username and password- the default for the username is admin (just type in admin) and for the password- motorola (just type in motorola).
And this is what you should see (for a working modem)- [Picture uploaded to costumer photos]
(This was taken after my issue was fixed).
Locate the Power column on the Downstream Bonded Channels table. See how they're all between 6 and 7? That's good. Now look at the power levels on the Upstream table- 34.000 dBmV, that's also good. Notice how all 8 lines of the Downstream table and all 4 lines of the upstream table are full, this means your channels are locked, this is the optimal situation.
Now, this is what I saw when my modem was working, but kept disconnecting ever so often- [Picture uploaded to costumer photos]
Notice now how the downstream power levels are negative, and that they are much closer, or over -8dBmV. Usually I'd see ranges between -7 and -9 when my modem wasn't working well (during the times when it was still able to maintain a connection). This is what the levels look like when your modem is barely hanging on to the connection. It manages to lock all downstream channels, but barely. Now look at the monstrous upstream power level- 55.7dBmV! This would usually be 57dBmV, and it was the source of all my problems, also notice that only one upstream channel is locked, this would usually show when looking at your modem lights- if all channels are locked the light would be blue. If they're not all locked, but the modem is still able to connect, the light would be green. What I'd normally see is a green light for power, a blue light for downstream (the second light down), a green light for upstream (the third light down), and a green light (sometimes flashing) for the 4th light.
If you compare this photo to the one where the modem is working perfectly you can see that the high upstream levels are effectively disrupting all the other channels, causing them to go negative. While this did not cause any decrease in speed, it did cause the modem to lose signal every 5 minutes, 10 minutes, 3 hours, etc.
One thing I'd like to mention here- somehow (and I have no idea how or why), this is not an issue with the modem *itself*, but rather with how it receives the signal from the cable company. When the issue was fixed, it was fixed on the cable line itself (outside my house), and nothing was done to the modem.
Alright, one last thing I'd like to show you- this is how your modem looks while it is disconnected, and cannot reconnect- [Picture uploaded to costumer photos]
Here what we're seeing is the modem struggling to lock on to a signal, in the photo the downstream power level is -7, but I've seen it anywhere between -9.9dBmv to 43.0dBmV, the upstream is 49dBmV, but I've seen that go all the way up to 57 as well. I'm really not sure what's happening *inside* the modem, but it's clear that something is wrong, since it would stay like this for a while (sometimes hours). The lights on the modem, by the way, will flash green when it's trying to connect like this (either the downstream or upstream light).
*solving the problem*
So, now that we've been able to diagnose, how do we *solve the problem?*
Well, sadly there is only one way- call your cable company, and ask for a technician. Most of the time this means you'll have to go through the proper channels, call support, talk to the guy from India trying his hardest to mask his accent (god bless these guys, they do try hard, and do a great job most of the time), and eventually when all fails tell them you're seeing very high/abnormal power levels, and that you definitely need a technician.
When the technician comes tell them you're seeing abnormal power signals. They'll connect their little modem to your cable line and see what they're getting, then they'll check all the wires, and eventually check the tap. They'll then either replace the cables around your house, or the cables connecting to the tap, or they'll have to call a line guy to work on it and fix it the next day.
Do not despair, these guys are usually very nice, and good at what they do. If the problem persists a week later, again, do not despair, just call them again, and tell them what's happening. If you can meet up with the actual line repairman, do so, and explain to them what the problem was.
Hopefully this will help you fix your line and get the steady connection I am getting.
By the way, I have found that remote fixes (where they call you and say "we've changed something in our files, not your internet should work better") do not work very well, or for long. If your internet is working after one of these repairs wait at least 3 days to see if problems eventually persist.
Well, I have to admit, I don't really have anything to compare this modem to- it works well, wifi range is wonderful, covers the whole house (2000sqft, cast walls), speeds are great, there are no drops anymore, and the modem/router seems to have many features which I don't really use like uPnP, port forwarding, etc. Pretty basic, pretty simple to understand. There's also the option of creating a guest network, which I guess is good for some specific uses, and there's also WPS, which might be useful to some people.
All in all does what it's meant to, and does it well, I guess. Not much to add, not much I know about routers or modems.