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SangreAngel
Posts: 1
Registered: ‎09-16-2011

SBG6580 modem problem? or Connection Problem?

Has a Comcast tech out the other day and he watched the levels for 15min said everything was fine. After he left problems with the modem dropping out and SOMETIMES coming backup by it self began again. Took my 1 month old modem back to BestBuy and got a brand new one. Same problem within 10 minutes. This is my specs and log information. Someone please give me an idea of what is going on and if anyone needs more information just let me know.

 

Motorola SBG6580 Modem/Wireless Router

 



Downstream Bonded Channels

Channel               Lock Status         Modulation        Channel ID          Frequency          Power   SNR

1              Locked  QAM256              1              651000000 Hz     1.5 dBmV            39.9 dB

2              Locked  QAM256              2              657000000 Hz     1.2 dBmV            39.7 dB

3              Locked  QAM256              3              663000000 Hz     0.7 dBmV            38.2 dB

4              Locked  QAM256              4              669000000 Hz     0.4 dBmV            39.1 dB

5              Locked  QAM256              5              675000000 Hz     0.5 dBmV            39.0 dB

6              Locked  QAM256              6              681000000 Hz     0.8 dBmV            39.4 dB

7              Locked  QAM256              7              687000000 Hz     1.0 dBmV            39.2 dB

 

 

Upstream Bonded Channels

Channel               Lock Status         US Channel Type              Channel ID          Symbol Rate       Frequency          Power

1              Locked  ATDMA                10           5120 Ksym/sec  36400000 Hz       47.5 dBmV

2              Not Locked         Unknown            0              0 Ksym/sec         0 Hz        0.0 dBmV

3              Not Locked         Unknown            0              0 Ksym/sec         0 Hz        0.0 dBmV

4              Not Locked         Unknown            0              0 Ksym/sec         0 Hz        0.0 dBmV

 

Event Log (Shortened)

 

 Fri Sep 16 16:29:55 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

Fri Sep 16 16:37:40 2011                  Notice (6)            TLV-11 - unrecognized OID;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:01:5c:24:b1:0e;CM-QOS=1.1;CM-VER=3.0;

 

 Time Not Established     Critical (3)            No Ranging Response received - T3 time-out 

 

 Fri Sep 16 16:35:46 2011                 Critical (3)            No UCDs Received - Timeout;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:35:26 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:34:38 2011                 Critical (3)            No UCDs Received - Timeout;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:34:18 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:33:30 2011                 Critical (3)            No UCDs Received - Timeout;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:33:10 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:32:24 2011                 Critical (3)            No UCDs Received - Timeout;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:32:04 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:30:52 2011                 Critical (3)            No UCDs Received - Timeout;;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 Fri Sep 16 16:30:33 2011                 Critical (3)            SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=1c:14:48:d3:ba:93;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;

 

 

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: SBG6580 modem problem? or Connection Problem?

The posted signals look good, very good in fact, that's a nice clean downstream signal.

 

There are, however, two signal values you cannot see at your modem.  Call Comcast and ask them for the upstream receive power and upstream SNR (signal to noise ratio) for your cable modem.  The power should be around 0, and the SNR should be north of 30.