New Poster
•
1 Message
What are normal signal levels?
Service interuptions multiple times a day. SB8200 Modem. Only one 2-way splitter installed by the tech.
Outage coincides with error log "Started Unicast Maintenance Ranging" followed by multiple "Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW" and "Dynamic Range Window violations"
After weeks of chats with tech support and the automated phone support that just wants to reboot my modem I finally got a live person who tells me you signal is within normal limits but can't tell me what those limits are. Obviously my modem doesn't agree.
I believe these downsteam numbers are on the ragged edge of being too low. The modem panics and rescans, causing the outage. I can't get any human tech support that knows enough to help me troubleshoot this. All the other posts I"ve found show signal levels in the positive range for DS and I'm -10 dBm or worse. If the system is asking for more upstream than the modem is willing to give, wouldn't that indicate a problem?
| Channel ID | Lock Status | Modulation | Frequency | Power | SNR/MER | Corrected | Uncorrectables |
| 38 | Locked | QAM256 | 721750000 Hz | -9.6 dBmV | 36.8 dB | 3476 | 2511 |
| 1 | Locked | Other | 780000000 Hz | -10.8 dBmV | 26.8 dB | 791041545 | 982 |
| 11 | Not Locked | QAM256 | 0 Hz | 0.0 dBmV | 39.8 dB | 3856 | 3415 |
| 12 | Locked | QAM256 | 559750000 Hz | -4.2 dBmV | 39.6 dB | 4147 | 3273 |
| 13 | Locked | QAM256 | 565750000 Hz | -5.2 dBmV | 39.4 dB | 4411 | 3122 |
| 14 | Locked | QAM256 | 571750000 Hz | -5.3 dBmV | 39.4 dB | 3892 | 3014 |
| 15 | Locked | QAM256 | 577750000 Hz | -5.4 dBmV | 39.1 dB | 3790 | 3121 |
| 16 | Locked | QAM256 | 583750000 Hz | -6.0 dBmV | 38.9 dB | 3837 | 3949 |
| 17 | Locked | QAM256 | 589750000 Hz | -6.8 dBmV | 38.5 dB | 3825 | 3991 |
| 18 | Locked | QAM256 | 595750000 Hz | -7.5 dBmV | 38.6 dB | 4148 | 3673 |
| 19 | Locked | QAM256 | 601750000 Hz | -7.3 dBmV | 38.5 dB | 4178 | 3844 |
| 20 | Locked | QAM256 | 607750000 Hz | -7.3 dBmV | 38.1 dB | 4219 | 4054 |
| 21 | Locked | QAM256 | 613750000 Hz | -8.4 dBmV | 37.5 dB | 4828 | 4500 |
| 22 | Locked | QAM256 | 619750000 Hz | -9.3 dBmV | 36.9 dB | 5940 | 4741 |
| 23 | Locked | QAM256 | 625750000 Hz | -10.4 dBmV | 36.9 dB | 5314 | 4858 |
| 24 | Locked | QAM256 | 631750000 Hz | -10.4 dBmV | 36.8 dB | 4473 | 4817 |
| 25 | Locked | QAM256 | 637750000 Hz | -10.6 dBmV | 36.8 dB | 4447 | 4414 |
| 26 | Locked | QAM256 | 643750000 Hz | -10.5 dBmV | 36.7 dB | 4107 | 4668 |
| 27 | Locked | QAM256 | 649750000 Hz | -10.7 dBmV | 36.5 dB | 4304 | 4650 |
| 28 | Locked | QAM256 | 655750000 Hz | -10.9 dBmV | 36.9 dB | 3951 | 4159 |
| 29 | Locked | QAM256 | 661750000 Hz | -10.3 dBmV | 36.9 dB | 5768 | 6746 |
| 30 | Locked | QAM256 | 667750000 Hz | -10.1 dBmV | 35.4 dB | 4897 | 5183 |
| 31 | Locked | QAM256 | 673750000 Hz | -10.3 dBmV | 36.6 dB | 4019 | 4320 |
| 32 | Locked | QAM256 | 679750000 Hz | -10.5 dBmV | 36.6 dB | 4168 | 4274 |
| 33 | Locked | QAM256 | 685750000 Hz | -10.4 dBmV | 36.6 dB | 4001 | 3982 |
| 34 | Locked | QAM256 | 691750000 Hz | -10.2 dBmV | 36.5 dB | 3954 | 3473 |
| 35 | Locked | QAM256 | 697750000 Hz | -10.5 dBmV | 36.5 dB | 23596 | 29249 |
| 36 | Locked | QAM256 | 703750000 Hz | -10.4 dBmV | 36.2 dB | 117800 | 200360 |
| 37 | Locked | QAM256 | 709750000 Hz | -10.7 dBmV | 36.5 dB | 7048 | 5432 |
| 39 | Locked | QAM256 | 715750000 Hz | -10.2 dBmV | 36.4 dB | 3682 | 3052 |
| 40 | Locked | QAM256 | 727750000 Hz | -10.1 dBmV | 36.2 dB | 3444 | 3100 |
| 41 | Locked | QAM256 | 733750000 Hz | -10.3 dBmV | 36.3 dB | 3595 | 2711 |
| Channel | Channel ID | Lock Status | US Channel Type | Frequency | Width | Power |
| 1 | 3 | Locked | SC-QAM Upstream | 23700000 Hz | 6400000 Hz | 41.0 dBmV |
| 2 | 1 | Locked | SC-QAM Upstream | 36500000 Hz | 6400000 Hz | 41.0 dBmV |
| 3 | 2 | Locked | SC-QAM Upstream | 30100000 Hz | 6400000 Hz | 41.0 dBmV |
| 4 | 4 | Locked | SC-QAM Upstream | 17300000 Hz | 6400000 Hz | 40.0 dBmV |
Current System Time: Tue Aug 11 09:17:39 2020
EG
Expert
•
106.2K Messages
4 years ago
Check your signal levels
To view your modem’s status page go to http://192.168.100.1 or http://10.0.0.1
Specification Min Max
Note: Not all modems will allow you to view the status page and some will have different URLs to access this info. If you are unable to access your modem’s status page, you can contact Comcast Customer Support and ask the support representative for these values.
0
0
EG
Expert
•
106.2K Messages
4 years ago
The downstream power is on the low / weak side and it may be intermittently fluctuating even lower to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.
In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test
If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.
0
0