Welcome to Comcast Help & Support Forums
Find solutions, share knowledge, and get answers from customers and experts

New to the Community? Start here.

5,440,725

members

32

online now

1,668,580

discussions

Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

Posted by
Visitor
  • The Community would like to Welcome you!

Member Since: ‎04-15-2012
Posts: 1
Message 1 of 7 (20,142 Views)

Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

I just got comcast high speed internet and i didnt want to pay $7 a month for the lease modem so i bought the SB6121 from newegg. However when try to activate the modem online the modem always reboots itself and i can activate. i honestly dont know if this is the internet's issue or the modems issue.

 

Any helpful tips you guys can spare me?

If the problem is the modem can you guys reccomend another one that a decent price?

 

-Eric (Jimmy is my dad's name)

6 REPLIES
Posted by
Edited on
‎04-15-2012 07:07 PM

Cable Expert

Member Since: ‎06-27-2009
Posts: 13,188
Message 2 of 7 (20,141 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

[ Edited ]

We need more information please:

- Post your upstream and downstream signal levels. Click the link or type: http://192.168.100.1 into your browser. We are interested in your power levels (dBmV) and your Signal to Noise Ratio (SNR). You may also want to contact Comcast and ask for your upstream SNR (uSNR) and receive level.

- Post your modem’s error logs.
- Post the make and model of your modem.
- Post the make and model of your router if you have one.
- Let us know if you contacted Comcast or had a tech visit.
- Let us know what the lights on your modem are doing when you are having problems.

Posted by
Bronze Problem Solver

Member Since: ‎12-05-2010
Posts: 3,418
Message 3 of 7 (20,137 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

Did the modem ever work? Did you call CC and ask them to set it up on your account? The computer set up process does not always work. call them tell them you want to set up your customer owned modem.

Posted by
Connection Expert

Member Since: ‎12-24-2003
Posts: 50,385
Message 4 of 7 (20,127 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem


Jim721 wrote:

Did the modem ever work? Did you call CC and ask them to set it up on your account? The computer set up process does not always work. call them tell them you want to set up your customer owned modem.


FWIW, If the modem is not in "block sync" mode they will not be able to see it or provision it for service.

Posted by
Visitor
  • The Community would like to Welcome you!

Member Since: ‎06-08-2012
Posts: 1
Message 5 of 7 (18,626 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

I am having the same problem.  On my second sb6121 so suspecting it is comcast.

Posted by
Visitor
  • The Community would like to Welcome you!
  • Great Job! Your reply has been accepted. Thank you for helping and Congrats on your 1st Solution.

Member Since: ‎06-08-2012
Posts: 8
Message 6 of 7 (18,598 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem

I had the same issue.  You actaully have to call Comcast and manually give them your modem's info. The web provisioning will not work. 

Posted by
Connection Expert

Member Since: ‎12-24-2003
Posts: 50,385
Message 7 of 7 (2,212 Views)

Re: Motorola SURFboard SB6121 DOCSIS 3.0 Cable Modem