Motorola SurfBoard Cable Modems

A few tips from someone who recently bought the SB6141 to replace a Comcast $10-a-month house brand:
0. This is not a router. If you’ve got your own wifi router, this should work with it… but if you’re just using the Comcast all-in-one modem for everything, you will need more than just this modem. There are other SurfBoard modems that come with wifi and routing as well, but this one’s on sale, and there is something to be said for keeping those functions separate.

  1. Yes, it’s compatible. As long as your plan isn’t more than around 300M down or 100M up, this should work just fine. I would recommend against the 6121–the price difference is only 10 bucks, and it could limit you if you ever upgrade to a plan with better than 100M down. Also, more channels will theoretically be a little more reliable, even at the same data rates–the 6121 only has 4 channels downstream, while the 6141 has 8.
  2. You shouldn’t need to call Comcast to get this installed. Just plug it all in, access the internet, and it should redirect you to the activation page.
  3. When returning your rent-a-modem, do not use the drop box. Take it to a human, get a receipt. Save the receipt until your bill comes through and the rental charge has definitely been taken off… and maybe save it after that, too. I am currently trying to get my bill amended, and I am not happy about it, but after a few months it’ll pay for itself and I’ll be saving $120 a year.

Attn mods: The Specs tab for the 6141 lists a maximum data rate of 131.072 Mbps (4 channels). This is true only for upstream–downstream on this device has 8 channels and twice the data rate.

Great info.

Around here, the Comcast offices have been dropping like Flies, so it’s tough to find one to take it to. The last time I took mine in, I called into the call center, and they let me take it to the UPS store. It was no cost to me, and from the UPS store they were able to scan it into the system and give me a receipt for the modem (a Comcast receipt), and take it back that way.

Yeah, this ended up being the best route for me. I didn’t even call customer service, I just walked in, gave them my old equipment and walked out with the receipt.

When I tried going to the local office to drop it off, the line was so long that people were lined up outside of the building. Hopefully I won’t have to put up a fight to get the rental charge removed.

Shouldn’t, but folks buying this shouldn’t be surprised if they run into issues - I certainly did. I went through three different SB6121 modems after I decided to stop paying Concast their monthly rental fee. Every time they would work fine for a day or two, then suddenly stop. Each time, the Comcast rep not only blamed the modem, but made a point of blaming all issues on it, and since it wasn’t Comcast tech, they wouldn’t troubleshoot it, and that I should consider renting their equipment again.

The third time (having purchased locally from a big box store, and returned it as defective each time), the same thing happened, I was given the same runaround, at which point I told them to cancel my service, and that I would be reporting them to the BBB. Lo and behold, the tech said “Oh wait, let me try one thing on my end…” and magically the modem has performed flawlessly ever since.

Long story short - this is an excellent piece of tech that WILL pay for itself in less than 6 months if you’re a Comcast customer renting their modem. As tafoxx said, you WILL still need a router if you’re connecting more than one device or need wireless (and who doesn’t?), nor does it provide phone service (I wholeheartedly recommend Ooma, which is often offered on Woot). Just be prepared to do the dance with Concast, as they REALLY don’t like losing money.

Yeah, it’s definitely a bit of a crap shoot. Mine registered fine, but was capping out at 80 Mbps for some reason. Had to power cycle it after a day had passed, and it got better–I assume a firmware update had downloaded.
And yes, this is not the right choice if you use voice service. I completely forgot about that.

TWC customer here, this is a great investment, I highly recommend it, however, TWC are harder than those of comcast… you have to call their CS line to get your modem activated… and believe me when I say, get your coffee, get your headset fully charged and get a ton of patience…
After my call being “accidentally” disconnected twice, I finally managed to get my modem activated, this time I had to wait for an hour.
but it is worth it

Just a little note too if you have one of those comcast all-in-ones or rent comcast equipment for your internet…

At least at the end of 2014, Comcast was using your equipment, whether you like it or not, to let others with comcast accounts use your internet as a hot spot. You’re potentially sharing your speeds with other people. Having your own equipment negates this and doesn’t let them do it. They’ve been sued by customers over this but I can’t find out if this is still an active thing they do or not. I KNOW someone in my apartment building has it turned on because when I look at my wifi availability choices, an “xfinitywifi” pops up open but then prompts me to log in to comcast to use it.

It’s mostly true that "…customers can turn them off by calling 1-800-XFINITY or online at" but there have been cases where customers can’t at Comcast’s fault. Their website is absolutely horrendous for reliability and having the correct pages where they need to be.

It is all around a good investment.

Once you have these hooked up run your speed tests. If you are getting consistent 30mbs and your service is higher speed you will need to call in and get them to make sure they get your settings to DOCSIS 3.0.

Love my 6141 running on TW. Speed is better than my subscription level.

TW website claims the approved modem registration is automated…it wasn’t. I had to call CS [Philippines] and he had to put me on hold while he side-barred with someone that had the tools to see the modem’s MAC on their network. Probably took 30 min and I kept them on the line long enough to test browsing, then re-boot and test again. YMMV.

I don’t recommend buying used or refurb modems. I’m a fan for refurbs for many other things but not modems for the simple reason that if someone used this at Comast before you and returned it, you will likely have a brick they will not authorize access to. It is a crap shoot. you feeling lucky?

Has anyone bought a refurb and successfully used it with comcast?

I found TW customer service is all over the map. When I called to get my 6121 activated it was a 3 minute phone call to give them my MAC address and watch the lights come up after a power-on. I renewed my DHCP address and I was online.

Here’s an easy way to avoid having to deal with these when you have a problem: get FIOS! If you don’t have that sweet 100% fiber optic network in your area (Verizon or Frontier is your local telco provider) then call your telco and see if they have VDSL or ‘Bonded’ ADSL in your area that will give you up to 40Mbps or more.

I’ll NEVER use the blood-sucking leeches at the cable company again!

Get FIOS he says, get bonded DSL he says. HA. Competition would be nice wouldn’t it.

My experience with TWC was somewhere in-between. I did have to wait a bit, maybe 10 minutes, while the rep went away, but they were very pleasant and the thing has worked great ever since.

One caveat, nothing to do with the unit but rather with TWC. Based on reports I read in previous discussion threads I was on the lookout for spurious charges from TWC. I returned their modem on 2/22, and as of the April bill they were still charging $8/month. A very nice rep took care of refunding the charges, and deleting it (supposedly) from future bills, but I will keep checking it, plus I scanned the receipt for the equipment return and saved it in cloud storage, ya never know when it will come in handy.

I bought one, and it was previously registered to a Comcast customer in Florida, so I had to return it. I bought a second, and woot sent me the wrong model. Both times, e form email I received said there were no others in stock to replace mine, and yet both times there it is on the website available for purchase! I must be a glutton for punishment, because I’m returning this one and buying one again.

Great Modem, HOWVER… CHECK WITH YOUR CABLE COMPANY FIRST! Yes, if you own your own modem you will pay for it within the first year and DOCSIS 3.0 is the latest cable internet tech. I own this modem and had a heck of a time getting Optimum/Cablevision to allow me to use it. So, before you spend the money, save yourself the headache and call your ISP and make sure that they will use it. Woot does not do returns and you will be stuck with it if your ISP does not honor it… Just a word of warning.

Help Folks - just saw these - what about Verizon or FIOS - how are these thingies with Fios please - eas hookup etc. I have 1 main box and 5 small ones and was trying to figure out how to do the antenna and Roku box procedures as I am paying waaaaay too much money to Verizon (also have a Droid - so figure close to 300 a month for internet and communications - errrr). Help Please?

thanks !

This modem is for CABLE ISPs, it won’t work for FIOS.

For those that want to avoid modem rental fees but you have home phone, this will still work. I was in line at a TWC service center a couple years ago and someone asked about it. As long as you have internet on the modem you pay the rental fee, once internet is dropped off the modem (if you go buy one of these), no more rental fee even if you have to keep it for home phone. This was a couple years ago and deserves verification.

On the topic of buying your own and getting support from the provider. I have TWC, bought the 6141 at retail 2 years ago and made the mistake of updating my router firmware right before setting up the modem. The firmware update caused problems that I initially associated with the modem. TWC humored me and sent a tech out TWICE to check the lines. After much griping, modem re-registrations and hair pulling I realized there were internal network issues also. Researched the FW update for the router and found others with similar issues so I rolled it back and it’s been PERFECT ever since.

FWIW, I pay for 30 Mbps from TWC and can download things faster at home than I can at work (for a Fortune 50 company).