Customer Reviews

249
4.5 out of 5 stars
ARRIS Touchstone Cable Modem CM820 DOCSIS 3.0 8x4
Price:$55.00 + Free shipping with Amazon Prime
Your rating(Clear)Rate this item


There was a problem filtering reviews right now. Please try again later.

90 of 96 people found the following review helpful
on February 22, 2013
Purchased this cable modem to replace my 6 year old Motorola SB5121 that I have rented from Comcrapstic the whole time. Doing the math on the total rental fees I have paid over the years yields an amount of OVER $500!!! No more rental fees. The other modem I was considering was the Mot SB6141...everyone knows about Motorola though. I chose the Arris based on the CM820A being a "3 star certified" modem per Comcrapstic's rating scale on their approved devices page. The second reason would be on the fact that Arris is a great manu of telephony/cable modems, this is mainly what they are known for.

Checking my speeds I am getting a solid and consistent 25 mbps down and 3.5 mbps up. This is phenomenal based on the fact that I am on the Performance tier. My power down is between 1.5-3 db with a 37-38 SNR on all 8 channels, awesome. My power up is 38 db, great. The interesting thing about that is that I split the signal twice before it goes to the modem, go figure. I am using PCT 2-way splitters on my setup.

***ALWAYS snug up ALL of your coax connections with a wrench***

Highly recommend the CM820A modem!!!

UPDATE 3/23/2015: Speeds are holding steady at 30 Mbps down and 6 Mbps up.

UPDATE 2/25/2015: The modem has been rock solid for going on two years now. No drops or connectivity issues. Very happy with the performance.

For all the people talking about not using a wrench on coax connections may have misinterpreted what I was "recommending." When I stated to "snug up all your coax connections with a wrench," I meant using a SMALL open-ended/combination wrench...not a torque wrench dialed into 150 ft lbs! If you use a small wrench and take it just past finger tight, that is all that is needed.
1212 commentsWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
31 of 34 people found the following review helpful
on February 19, 2014
Verified Purchase
Bought this knowing this modem might not work because of the negative comments made by others, but it turned out to be working great. I called Comcast and gave them the information to activate the modem and in less than 30 min it works. I saved $8 a month from rental fees and return the rental to Comcast the same day!!!!!
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
30 of 33 people found the following review helpful
on June 26, 2013
Verified Purchase
I wanted to take advantage of the faster Docsis 3.0 and stop paying rental on the modem I had with Comcast. This modem arrived really fast and was easy to install. After installing it, it would not connect to the internet until I had Comcast activate it. I had to call Comcast support and tell them I replaced my modem with a new one and within a few minutes they had me going. (You need to give them the serial number and MAC address of the new modem). The lady at Comcast also took the $6 monthly rental off of my account at the same time. The modem can sit either flat like shown in the picture or on edge. It also has mounting channels in the back so it could be mounted on a wall.

I confirmed the download speed increase using speedtest.net and my speed went from around 14MB/sec before to around 24MB/sec after. I have had this modem for several weeks now and it has been working great. No problems.
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
82 of 100 people found the following review helpful
on March 9, 2013
Verified Purchase
First I was switching DSL 3mb to Comcast 20mb and had a Motorola SB 6120 based on the reviews which I purchased at BB. The modem refused to lock for online no matter what I tried. So I purchased the Arris CM820 based on Comcast 3 star rating and 1PV4 & 6 compatibility. I wanted this to work as future proof for the next 5-10 years.

Unfortunately I checked Arris web site and they will only warranty their products if purchased from Cable provider or BB.

The comcast contractor who was sent out to assist with the SB6120 was unable to connet it and then we tried the Arris CM820 and while trying to get provisioning for the modem we were informed the SN was already registered with Comcast locally. They refused to provision the new modem fresh out of the sealed bag. The Comcast contractor then shared that the Arris Modems are allocated by states saying a Michigan modem would not work in Indiana. What the HE** you would figure a Cable Modem is a cable modem and you could take it anywhere you moved.

The Arris CM820 is on its way back to Amazon. I am going to see if a coworker can use the SB 6120.

Meanwhile I have an Arris WMB 760 rental...

Seems like there is a monopoly market here on modems...

Buyer beware!
1010 commentsWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
62 of 77 people found the following review helpful
on April 8, 2013
A call to Arris verified what the other reviewer said: Arris has no retail outlets. They sell their modems only to cable companies. Ostell, aModem, ElectroMax and the other sellers selling these units on Amazon are not authorized, and you may end up with a used modem.

Added later: Arris has apparently purchased Motorola's modem business. Motorola modems are sold to the public. When you see the brand name given as "Arris Motorola", you are looking at a Motorola modem. However, apparently only WHITE Motorola modems are sold to the public. The black ones are made for sale to cable companies. So even if it costs a little extra, you should buy a WHITE modem if you are getting the Arris Motorola brand.
66 commentsWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
10 of 10 people found the following review helpful
on January 23, 2014
Verified Purchase
ARRIS is a company that acquired Motorola's modem manufacturing, and this is a great modem which is small and has a built in power supply, so it has no adapters or power bricks. It was small enough for me to install in a patch panel in my house so I never need to see it, and it's been up and running for at least 6 months now, and I haven't had to reset it once. I've hit speeds of over 70 megabits with this, and that's limited by my ISP.
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
8 of 8 people found the following review helpful
on October 5, 2013
Verified Purchase
Replaced the same model owned by Time Warner Cable, so now I have no rental fee! This one works as well as the other.
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
4 of 4 people found the following review helpful
on March 18, 2015
Verified Purchase
I got the modem in 2 days on prime. Called cox cable and they told me it wasn't on the approved model list and could not do anything for me. Chatted with another cox rep online and they told me I "had" to purchase the modem through them. I told him, he was full of $%^&. Called cox back and gave them the ARRIS model SB6141 which is on the approved list. Gave them the serial and mac off the modem and a couple min later I was in business. Moral of the story, tell them it is the sb141 or an arris like model on their approved list and you will be good to go. Getting the speed I pay for 50mbps.
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
6 of 7 people found the following review helpful
on November 12, 2013
We bought one of these this past summer and it started acting wonky after about 3 months, then got progressively worse. Had to replace it last week as it could not hold a signal and was constantly trying to download firmware it already had- we needed to reset it every hour or more, and it was super slow. Two Comcast techs came out and neither could fix it; they suggested we replace. Worse yet, can't return it to Amazon or Arris- there is essentially no warranty on this item. AVOID !!!
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse
5 of 6 people found the following review helpful
on October 29, 2013
Verified Purchase
The process with the seller was excellent. Good price, fast shipping, and answered questions in a timely manner. Also provided a refund immediately upon request.

That being said, I was lured by the low price and did not do enough research. According to what I found online after having problems, this specific modem is offered only by cable companies and should not be available as a retail item. Others were having difficulty with duplicate CMAC addresses and their modem being registered more than once on different accounts as a result. I believe this is what happened with me. After connecting my modem and registering it with Comcast, I started having connectivity problems. About every other day my connection would go down and I would call Comcast. Each time I did, they told me there was no modem registered with my account. I would re-register it and the same problem would persist in about 24 to 48 hours.

At first, I was furious with Comcast. However, I did not have any issues like this with my previous modem and decided to look into the modem itself as a cause. After discovering other consumers who purchased this model modem from an online seller were having similar issues, I decided to purchase a modem from a local retail store. After purchasing a different make/model of modem from Best Buy and connecting it the connection problems ceased. I have now had the other modem for about a week with no problems. I tried with this ARRIS for nearly a month and the issue persisted.

Beware, do not be lured by the low price as I was. Save yourself some aggravation and purchase a retail model from a retail store.
0CommentWas this review helpful to you?YesNoSending feedback...
Thank you for your feedback.
Sorry, we failed to record your vote. Please try again
Report abuse

Questions? Get fast answers from reviewers

Please make sure that you've entered a valid question. You can edit your question or post anyway.
Please enter a question.
See all 56 answered questions


Send us feedback

How can we make Amazon Customer Reviews better for you?
Let us know here.

Your Recently Viewed Items and Featured Recommendations 
 

After viewing product detail pages, look here to find an easy way to navigate back to pages you are interested in.