Troubleshooting Internet Connection issues with the SB6190

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If Internet connection issues with the SB6190 arise, troubleshooting may resolve the issue, or may provide insight as to what is causing the issue.  This document provides helpful information for troubleshooting Internet connection issues with the SB6190.

The following troubleshooting steps are to be followed in sequence:

  1. Check the physical connection
  2. Verify the LEDs
  3. Power Reset
  4. Factory Reset
  5. Verify the cable signal
  6. NOTE: If the solutions provided in this document do not resolve the issue, please contact the cable operator for assistance.

Check the physical connection

  1. Verify that the SB6190 power cord is connected from the power port of the SB6190 to the power outlet.
  2. Verify that the coaxial cable is connected from the cable port of the SB6190 to the cable outlet.
  3. Verify that the Ethernet cable is connected from the Ethernet port on the SB6190 to the Ethernet port on the computer.User-added image

Verify the LEDs

With the proper setup, the Online LED should be solid green.  If this is not the behavior that the SB6190 is displaying, please refer to this table for more information regarding LED behavior.

User-added image

Power Reset

  1. Shutdown the computer.
  2. Unplug the cable modem from the AC wall outlet and wait one minute.
  3. Plug the cable modem into the wall outlet.
  4. Wait until the Power, Receive, Send, and Online LEDs are solid.
  5. Restart the computer.

Factory Reset

  1. Disconnect the coaxial cable.
  2. Power cycle the unit by disconnecting the power cord for 10 seconds, then reconnect the power cord.
  3. Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter http://192.168.100.1 into the address box.  The Status page will appear.User-added image
  4. Click the Configuration link on the top menu.  The Configuration page will appears.
  5. On the Configuration page, click the Restore Factory Defaults button (as shown below).
  6. When asked, Do you want to proceed?, click the OK button.User-added image
  7. Connect the coaxial cable to the modem.NOTE: The initialization process may take 5 to 30 minutes.

Verify Cable Signals

  1. Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter http://192.168.100.1 into the address box.  The Status page will appear.
  2. In the Downstream Bonded Channels section, verify Power levels are within the acceptable range of – 15 dBmV to + 15 dBmV for each downstream channel.Right click on the image to save it to your computer.
  3. In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel.Acceptable SNR Levels (dB):
    If QAM64, SNR should be 23.5 dB or greater.
    If QAM256 and DPL( -6 dBmV to +15 dBmV) SNR should be 30 dB or greater.
    If QAM256 and DPL(-15 dBmV to -6 dBmV) SNR should be 33 dB or greater.Right click on the image to save it to your computer.
  4. In the Upstream Bonded Channels section, identify the number of ChannelsTypeSymbolic Rate to find verify Upstream Power levels are within the acceptable range for each upstream channel.Acceptable Upstream Power Levels (dBmV):Right click on the image to save it to your computer.
    Upstream Transmit Power Level
    Channel US Channel Type Symbol Rate Acceptable US Power Level
    Single TDMA 1280 Ksym/sec +61 dBmV to 45 dBmV
    ATDMA 2560 Ksym/sec +58 dBmV to 45 dBmV
    5120 Ksym/sec +57 dBmV to 45 dBmV
    Two TDMA 1280 Ksym/sec +58 dBmV to 45 dBmV
    ATDMA 2560 Ksym/sec +55 dBmV to 45 dBmV
    5120 Ksym/sec +54 dBmV to 45 dBmV
    Three or more TDMA 1280 Ksym/sec +55 dBmV to 45 dBmV
    ATDMA  2560 Ksym/sec +52 dBmV to 45 dBmV
     5120 Ksym/sec +51 dBmV to 45 dBmV
  5. Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power.NOTE: If the either of the signal levels are outside of the acceptable range, power cycle or factory reset the modem.
  6. Contact the cable provider to adjust the signal level to the acceptable level range.

Acceptable Signal Levels

Recommended Max Downstream
Power Level (DPL)
Recommended Min Downstream
Power Level (DPL)
+15 dBmV -15 dBmV
Downstream Signal to Noise Ratio (SNR)
Modulation Downstream Power Level Acceptable DS SNR
64 QAM n/a 23.5 dB or greater
256 QAM -6 dBmV to +15 BmV 30 dB or greater
-6 dBmV to -15 dBmV 33 dB or greater
Upstream Transmit Power Level
Channel US Channel Type Symbol Rate Recommended Max US Power Level Recommended Min US Power Level
Single TDMA 1280 Ksym/sec +61 dBmV 45 dBmV
ATDMA 2560 Ksym/sec +58 dBmV 45 dBmV
5120 Ksym/sec +57 dBmV 45 dBmV
Two TDMA 1280 Ksym/sec +58 dBmV 45 dBmV
ATDMA 2560 Ksym/sec +55 dBmV 45 dBmV
5120 Ksym/sec +54 dBmV 45 dBmV
Three or more TDMA 1280 Ksym/sec +55 dBmV 45 dBmV
ATDMA 2560 Ksym/sec +52 dBmV 45 dBmV
5120 Ksym/sec +51 dBmV 45 dBmV