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Forum Discussion
NightHawkNancy
Mar 07, 2022Guide
C7800 Keeps Disconnecting and/or Very Slow
Our C7800 Nighthawk cable modem router recently started disconnecting or getting VERY slow speeds out of the blue. We purchased it in April 2021 and it worked flawlessly up until the middle of last m...
plemans
Mar 07, 2022Guru - Experienced User
You have errors in the cable connections page plus your logs are indicating issues.
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. I know you said you don't have an outlet but grab an extension cord and try the connection.
- NightHawkNancyMar 08, 2022Guide
Thanks for the reply plemans ! I removed the splitter from the coax line and connected the Nighthawk directly to where coax comes into the house. Cable appears to be in good condition. WiFi dropped out multiple times since moving it.
Below is the latest Cable Connection report and Event Logs. Does this appear to be a hardware issue or ISP issue?
Cable ConnectionFrequency start Value This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect. Starting Frequency <tabindex=-1>Startup Procedure</tabindex=-1> Procedure Status Comment Acquire Downstream Channel 747000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security ENABLED BPI+ IP Provisioning Mode Honor MDD IPv4 only <tabindex=-1>Downstream Bonded Channels</tabindex=-1> Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectabables 1 Locked QAM256 31 747000000 Hz 7.3 dBmV 40.1 dB 278 116 2 Locked QAM256 1 561000000 Hz 9.5 dBmV 42.3 dB 0 0 3 Locked QAM256 2 567000000 Hz 9.9 dBmV 42.8 dB 0 0 4 Locked QAM256 3 573000000 Hz 10.5 dBmV 42.9 dB 0 0 5 Locked QAM256 4 579000000 Hz 10.7 dBmV 43.0 dB 0 0 6 Locked QAM256 5 585000000 Hz 11.1 dBmV 42.9 dB 0 0 7 Locked QAM256 6 591000000 Hz 11.4 dBmV 43.1 dB 0 0 8 Locked QAM256 7 597000000 Hz 11.7 dBmV 43.2 dB 0 0 9 Locked QAM256 8 603000000 Hz 11.4 dBmV 42.8 dB 0 0 10 Locked QAM256 9 609000000 Hz 10.8 dBmV 42.5 dB 0 0 11 Locked QAM256 10 615000000 Hz 10.4 dBmV 42.6 dB 0 0 12 Locked QAM256 11 621000000 Hz 10.3 dBmV 42.1 dB 0 0 13 Locked QAM256 12 627000000 Hz 10.2 dBmV 42.3 dB 0 0 14 Locked QAM256 13 633000000 Hz 10.0 dBmV 42.3 dB 0 0 15 Locked QAM256 14 639000000 Hz 10.3 dBmV 42.3 dB 0 0 16 Locked QAM256 15 645000000 Hz 10.6 dBmV 42.1 dB 0 0 17 Locked QAM256 16 651000000 Hz 10.9 dBmV 42.3 dB 0 0 18 Locked QAM256 17 657000000 Hz 11.3 dBmV 42.4 dB 0 0 19 Locked QAM256 18 663000000 Hz 11.5 dBmV 42.4 dB 0 0 20 Locked QAM256 19 669000000 Hz 11.2 dBmV 42.3 dB 0 0 21 Locked QAM256 20 681000000 Hz 10.5 dBmV 42.1 dB 0 0 22 Locked QAM256 21 687000000 Hz 10.1 dBmV 41.9 dB 0 0 23 Locked QAM256 22 693000000 Hz 9.7 dBmV 41.9 dB 12 0 24 Locked QAM256 23 699000000 Hz 9.6 dBmV 42.0 dB 11 0 25 Locked QAM256 24 705000000 Hz 9.4 dBmV 41.7 dB 9 0 26 Locked QAM256 25 711000000 Hz 9.4 dBmV 41.9 dB 54 0 27 Locked QAM256 26 717000000 Hz 9.4 dBmV 41.8 dB 50 0 28 Locked QAM256 27 723000000 Hz 9.6 dBmV 41.8 dB 65 30 29 Locked QAM256 28 729000000 Hz 9.5 dBmV 41.8 dB 112 46 30 Locked QAM256 29 735000000 Hz 9.1 dBmV 41.5 dB 108 96 31 Locked QAM256 30 741000000 Hz 8.3 dBmV 41.1 dB 149 75 32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 <tabindex=-1>Upstream Bonded Channels</tabindex=-1> Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 5 2560 Ksym/sec 18000000 Hz 39.5 dBmV 2 Locked ATDMA 7 5120 Ksym/sec 31000000 Hz 41.8 dBmV 3 Locked ATDMA 6 5120 Ksym/sec 24600000 Hz 40.8 dBmV 4 Locked ATDMA 8 5120 Ksym/sec 37400000 Hz 43.0 dBmV 5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV 6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV 7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV 8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV <tabindex=-1>Downstream OFDM Channels</tabindex=-1> Channel Channel ID Indicator Subcarrier Zero Frequency Active Subcarrier Number Range Total Codewords Uncorrectable Codewords 1 32 Non-Primary 428600000 Hz 1528 ~ 2567 192437 525 2 0 Other 0 Hz 0 ~ 0 0 0 <tabindex=-1>Upstream OFDMA Channels</tabindex=-1> Channel UpstreamIsMuted Ranging Status Subcarrier Zero Frequency Active Subcarrier Number Range Symbols Per Frame Tx Power 1 Other 0 Hz 0 ~ 0 0 0 dBmV 2 Other 0 Hz 0 ~ 0 0 0 dBmV Current System Time: Tue, Mar 08, 2022 16:40:42 EVENT LOGTime Priority Description 2022-03-08, 12:26:25 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-08, 12:26:21 Notice (6) TLV-11 - unrecognized OID;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Warning (5) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) DHCP FAILED - Discover sent, no offer received;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv4 Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2022-03-08, 11:52:22 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) DHCP FAILED - Discover sent, no offer received;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) DHCP FAILED - Discover sent, no offer received;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:22:34 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:17:43 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:17:43 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:17:33 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:17:28 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 16:17:28 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 14:05:56 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 13:52:38 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 11:24:03 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2022-03-07, 11:20:49 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:87:d9:b0;CMTS-MAC=00:01:5c:b7:10:91;CM-QOS=1.1;CM-VER=3.1; - NightHawkNancyMar 08, 2022Guide
FURRYe38 any suggestions on my issue here?
- plemansMar 08, 2022Guru - Experienced User
You've still got some indications of line problems in the logs. And now your power is a touch high.
Not sure what splitter you had in line but your power jumped significantly from removing the one you have.
Try putting a decent quality double splitter back in line. Maybe a triple.
Just make sure its a decent quality. the channels you had issues with (hz not just channel number) cleared up but now others have errors.
Try that first.
and once you do that, clear the logs out so we know that anything new on there is from after the change. Not sure if you're log has events from befor the change.
If it doesn't help, the isp might need to check the line.