signal loss from cable modem

budafuco · Post by **budafuco** » Wed May 31, 2006 10:45 pm

I had some problems with my signal being lost last summer but they had gone away during the winter. Now it is summer again and the problem is back and its much much worse. The cable modem will lose the signal and reset sometimes every minute. Very frustrating.
I have a Motorola surfboard sb5120 modem and this is my current information:

Frequency 579000000 Hz
Signal to Noise Ratio 37 dB
QAM QAM256
Network Access Control Object ON
Power Level -1 dBmV
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

Upstream Value
Channel ID 2
Frequency 22800000 Hz
Ranging Service ID 532
Symbol Rate 2.560 Msym/s
Power Level 42 dBmV

In the logs I get this:
3-Critical R02.0 No Ranging Response received - T3 time-out

The line comes from outside into the attic where it splits into two, one line goes directly to the modem and the other line goes to another splitter which then goes to all the TV's.
Is there any hope of fixing this myself or I am gonna have to call my tech support out again. They didn't fix it last summer.

Also, I live in Phoenix where it gets 100+ degrees outside. The attic where the cable runs gets even hotter. Could temperature play a role in the signal dropping out? I just can't imagine why the signal loss would have gone away for the winter and come back again in the summer.

Thanks

buckifan · Post by **buckifan** » Thu Jun 01, 2006 9:23 am

Your signal levels look fine. I don't understand when you say the signal gets lost. It is normal for signal levels to change with temperature, but only a few db.

The log entry "3-Critical R02.0 No Ranging Response received - T3 time-out" is normal as long as the log isn't filled with these. What other log entries do you have?

budafuco · Post by **budafuco** » Thu Jun 01, 2006 4:11 pm

What I meant by signal loss, is, its as if I disconnected the coaxial cable from the back of the modem. The internet will stop working and then a few seconds later the modem will reset. Sometimes it does this a lot, sometimes not. I traced the line all the way to outside and nothing seems to be damaged. Thanks for the help.

2006-06-01 13:04:28 7-Information SNMP: Working in SNMP V1/2c Only NmAccess mode
2006-06-01 13:04:26 7-Information INITIALIZATION COMPLETE - MODEM IS OPERATIONAL
2006-06-01 13:04:26 7-Information B401.0 Authorized
2006-06-01 13:04:26 7-Information SEC: Co-Signer CVC from configuration file was verified
2006-06-01 13:04:25 7-Information REGISTRATION COMPLETE - Waiting for Operational status
2006-06-01 13:04:24 7-Information REG: Capability type <16> incorrectly negotiated by CMTS
2006-06-01 13:04:24 7-Information Registration file - downloaded
2006-06-01 13:04:23 7-Information Trying to download Configuration file ...
2006-06-01 13:04:23 7-Information Time of day - retrieved
2006-06-01 13:04:23 7-Information DHCP - parameters acquired
2006-06-01 13:04:23 7-Information DHCP: ACK: Setting (*) CM TFTP Boot file: DEF001_vm1.1_d.cfg
2006-06-01 13:04:23 7-Information DHCP: Setting CM IP address to: 10.49.211.231
2006-06-01 13:04:22 7-Information DHCP: Setting (*) CM Syslog Server address to: 172.19.73.16
2006-06-01 13:04:22 7-Information DHCP: Setting (*) CM Time Server address to: 172.19.73.16
2006-06-01 13:04:22 7-Information DHCP: Setting (*) CM Subnet mask to: 255.255.248.0
2006-06-01 13:04:22 7-Information DHCP: Setting (*) CM Gateway address to: 10.49.208.1
2006-06-01 13:04:22 7-Information DHCP: OFFER: Setting (*) CM TFTP Boot file: DEF001_vm1.1_d.cfg
2006-06-01 13:04:22 7-Information DHCP select: Setting (*) CM TFTP Server address to: 172.19.73.16
2006-06-01 13:04:22 7-Information DHCP: Offered (*) CM IP address to: 10.49.211.231
2006-06-01 13:04:20 7-Information Trying to register through CMTS...
Event Log has reached maximum size. Older log entries are lost.

buckifan · Post by **buckifan** » Thu Jun 01, 2006 6:12 pm

This could be a tough one to troubleshoot. When the modem starts reseting a lot check your TV picture for noise or anything unusual. Do you have a set-top-box and, if so, have you had problems with it during hot weather. Do you have any neighbors that use your service? Check to see if they are also having problems.

Finally, your ISP has the ability to monitor your connection for problems by checking the flap list at the CMTS. This would be the best way to troubleshoot a problem like this one.

budafuco · Post by **budafuco** » Fri Jun 02, 2006 1:10 am

Thanks for the reply. A guy came out today and removed some unneeded equipment and hooked the cable back up. The internet has been stable ever since. I wish I could elaborate more but I have no idea what it was that he removed. Regardless, my internet stays on so I am happy. Thanks again.