Reply
New Visitor
SpiderIce
Posts: 3
Registered: ‎06-27-2013

Cable Modem Reboot due to T4 timeout

Cable modem rebooting many times a day. Do to T4 issues and have had many tech's come and check my connection. They all tell me my levels are good, but my connection drops randomly about 20 or more times a day for 1-2mins then it runs good until the next drop. This has been going on for about 1 month.

 

Many parts of my connection have been replaced by this point, new connecters, new splitter, new cable from splitter to modem, new modem

 

Started with an SB6121 modem, I just replaced it with SB6141 and this is still going on. I have a Cisco DPC3008 coming in a few days but don't think its modem related any longer. 

 

What other things can I try or how can I escalate this issue? I seem to be just going in a loop now to the point I'm having to call comcast every day to report the issue and then get 1-2 day wait for a tech.

 

Jan 01 1970 00:00:58 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted

Jan 01 1970 00:00:58 3-Critical R03.0 Ranging Request Retries exhausted

Jan 01 1970 00:00:55 3-Critical R02.0 No Ranging Response received - T3 time-out

Jan 01 1970 00:00:14 6-Notice N/A Cable Modem Reboot due to T4 timeout 

Cable Expert
i-am-nerdburg
Posts: 11,036
Registered: ‎06-27-2009

Re: Cable Modem Reboot due to T4 timeout

We need more information please:

- Post your upstream and downstream signal levels. Click the link or type: http://192.168.100.1 or http://10.0.0.1 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.
- If you have already posted some of this information, you don't need to post it again.

New Visitor
SpiderIce
Posts: 3
Registered: ‎06-27-2013

Re: Cable Modem Reboot due to T4 timeout

[ Edited ]

 

Channel ID 1  2  3  4  5  6  7  8 

Frequency 687000000 Hz  693000000 Hz  699000000 Hz  705000000 Hz  711000000 Hz  717000000 Hz  723000000 Hz  729000000 Hz 

Signal to Noise Ratio 36 dB  36 dB  36 dB  36 dB  36 dB  36 dB  36 dB  36 dB 

Downstream Modulation QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256 

Power Level The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading 3 dBmV   3 dBmV   3 dBmV   3 dBmV   3 dBmV   3 dBmV   2 dBmV   2 dBmV  

 

 

Channel ID 11  10  12 

Frequency 29500000 Hz  36400000 Hz  24200000 Hz 

Ranging Service ID 12535  12535  12535 

Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  2.560 Msym/sec 

Power Level 45 dBmV  45 dBmV  43 dBmV 

Upstream Modulation [3] QPSK
[3] 64QAM
  [3] QPSK
[3] 64QAM
  [3] QPSK
[2] 16QAM
  Ranging Status Success  Success  Success 

 

 

Router is: ASUS RT-AC66U running DD-WRT

Nothing on router stops working, WiFi or local network ever drops when issue hits.

 

Modem light's are (when problem happens after all the lights drop but power):

  • Solid Green Power
  • Solid Green Down Stream 
  • Blinking Blue Up Stream
  • No Internet Light
  • Blinking Blue ethernet

 

Some times Down and Up changes then changeds back:

  • Blinking Blue Down
  • No light on Up
  • all other lights the same as before

 

 

New Visitor
Untoward
Posts: 1
Registered: ‎07-27-2013

Re: Cable Modem Reboot due to T4 timeout

Any action on this?  I have the same problem.

New Visitor
Frustration-Hi
Posts: 1
Registered: ‎08-08-2013

Re: Cable Modem Reboot due to T4 timeout

I have been having the same T-4 timeout issue since moving here 12 days ago.  Each time I call Comcast they tell me the wait time is 2 or 3 days for a tech to come out and look at my modem.  The case was escalated last week, the escalation group decided to do nothing and close the ticket.  They never contacted me.  I think it is time to find another carrier, these people are spinning their wheels.

New Visitor
Jamwae
Posts: 2
Registered: ‎08-14-2013

Re: Cable Modem Reboot due to T4 timeout

did the Cisco Model solve your issue, SpiderIce?

New Visitor
SpiderIce
Posts: 3
Registered: ‎06-27-2013

Re: Cable Modem Reboot due to T4 timeout

No, my issues was in the main line outside up the pole.
New Visitor
Jamwae
Posts: 2
Registered: ‎08-14-2013

Re: Cable Modem Reboot due to T4 timeout

good to know. Thanks!

New Visitor
jedards
Posts: 1
Registered: ‎08-26-2013

Re: Cable Modem Reboot due to T4 timeout

I'm having the same problem with the following equipment:

 

Modem: Motorola SB6121

Router: ASUS RT AC66U

 

Channel ID 1  3  5  6  Frequency 333000000 Hz  345000000 Hz  357000000 Hz  363000000 Hz  Signal to Noise Ratio 35 dB  35 dB  35 dB  36 dB  Downstream Modulation QAM256  QAM256  QAM256  QAM256  Power Level The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading -6 dBmV   -6 dBmV   -6 dBmV   -5 dBmV  

Upstream Bonding Channel Value Channel ID 14  13  15  Frequency 27900000 Hz  21000000 Hz  34800000 Hz  Ranging Service ID 15344  15344  15344  Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  Power Level 51 dBmV  51 dBmV  51 dBmV  Upstream Modulation [3] QPSK
[3] 64QAM
  [3] QPSK
[3] 64QAM
  [3] QPSK
[3] 64QAM
  Ranging Status Success  Success  Success 

Signal Stats (Codewords) Bonding Channel Value Channel ID 1  3  5  6  Total Unerrored Codewords 51331347  51331007  51329121  51330168  Total Correctable Codewords 251  257  304  380  Total Uncorrectable Codewords 2590  2913  4818  3639 

New Visitor
chung5galactic
Posts: 1
Registered: ‎03-12-2014

Re: Cable Modem Reboot due to T4 timeout

I had the same issue.  It worked fine most times but

every few hours seems to get this T4 timeout.

Tried replacing the CMD31T modem with SB6141.

No luck.  At least the SB6141 allowed me to access its status page.

 

But then I noticed a couple of weeks ago that the cable going

up into the atttic was bent and pulled out of the fastener by about 1/4 inch.

So someone (probably the workers who were working to remove the trees

and shrubbery aroud the house) had pulled it out rather strongly

and probably damaged it somewhat.   And I think the connection was bad when it

was windy and the wind moved the cabling around, is my guess.

(It was windy a few weeks back.)

 

After I just moved it around a bit and straightenned the cable out, I have had

no T4 timeouts for more than a week.... Prob should replace the cable someday.

 

Cheers,


Chung