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Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

Frequent Visitor

Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

I have a new Arris SBG8300 and I randomly lose Internet connection. I have tried both a Wireless Adapter and Ethernet. Both do the same thing. Usually in about 20-30 minutes and the time does vary but mostly in 20-30 the Internet connection drops. I have talked to both Arris and Xfinity and Arris said that the QAM Upstream Power level should be between 47-49 for Optimum performance. It requires a Minimum of 45. The power level usually is 45 but sometimes is only 44. Arris said that if there is and fluctuation in the Power where it goes below 45 then it will drop connection. Xfinity sent somebody to check the outside lines and he said they were OK. He also said that he doesn't know why I was told about the power level because 25 to 37 was fine. Not if you read th Arris SBG8300 Specs they Explicitly State that the minimum is 45. I am pretty sure the power level is the problem. How can I get Xfinity to acknowledge that and Boost the Poer level to 47-49 or higher?

New Poster

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

Literally having the same exact issue with the same modem. I have a friend that works in Comcast look at my numbers and said they are fine and I was noticing my power at 41-44 but never the 45 minimum as you said and Arris told me as well. It's worked great for the couple months we've had service and just started doing the drop nonsense since Sunday. I've seen on another thread that the Bay Area, CA is having issues so maybe they are just overworking their network. Everything is fine if I reboot my modem. I've been told by more than one CSR it's my modem but Arris says it's Comcast's service. I've had 11 failures today since Noon and will start the log over before I go to bed.

Sorry to hear you are having the same issue but feel better than I'm not alone. Just wish there were competent people taking a look at the issue.

New Poster

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

Having the exact same issues with the same modem. Just upgraded to 1 GB service and upgraded to the SBG8300. Since that change internet drops for 3-5 minutes at a time at random time gaps which are normally less than 1 hour.

The down stream channels are all locked except channel 2 which is not locked. Channel has 559030611 unerrored codewords and has 3735936685 correctable and the same 3735936685 of uncorrectable codewords. All other channels have about 36,000 unerrored codewords and 0 for both correctable and unccorrectable. .

Have had about 10 calls with comcast at this point. Bought a 2nd SBG8300 to see if that was the issue but having the same symptoms. Have had  a tech out who checked all wiring and replaced a splitter but nothing has changed.


Frequent Visitor

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

SBG8300: Troubleshooting Internet Connection




How do I troubleshoot Internet connection issues with my SBG8300 Gateway?



If all the client devices in the home network have lost Internet connectivity, troubleshooting may resolve or provide insight on the cause of the issue.  This document provides helpful troubleshooting steps for Internet connectivity issues with the SBG8300.

Troubleshooting on the SBG8300 is not needed if the following scenarios are applicable:

  • First Time Setup
    For first time installation of the SBG8300 in a home network, following the installation steps in the article #17912 - SBG8300: Installation Setup.
  • At Least One Client Device with Internet Access
    The SBG8300 is connected to the Internet if at least one client device in the home network can access the Internet.  Connect the clients without Internet access to the SBG8300 with an Ethernet cable or to the Wi-Fi network.  Additional troubleshooting may be needed on the client without Internet.

The following troubleshooting steps are to be followed in sequence:

  1. Check the Power Supply
  2. Check the Gateways LED Light Status
  3. Power Cycle the Gateway
  4. Check the Cable Signal levels
  5. Reset to Factory Defaults 

Check the Power Supply
Use the power supply included with the SBG8300.  Overall functionality and performance cannot be guaranteed if the incorrect power supply is used when installing the SBG8300.  When using the incorrect power supply, the SBG8300 may get online and function, but firmware upgrades will not complete successfully.  

Check the Gateways LED Light Status
First step in troubleshooting is to check the 2 LEDs located on the front of the SBG8300.  Reference the table below to identify the possible issue for each LED status and perform the steps listed under Possible Solutions.  The detailed troubleshooting steps for power cycle, check cable signal levels and reset to factory defaults are available below the LED Light Status table.



Possible Issues

Possible Solutions



Wi-Fi cable modem is not properly plugged into the electrical wall outlet

  1. Check for damages on the power cord.
  2. Connect the power cord from the gateway and to an electrical outlet.
  3. Check that the electrical outlet is working; if controlled by a wall switch, confirm the wall switch is on.
  4. Try a different electrical outlet.


IP registration is unsuccessful

  1. Check each end of the coaxial cable connection of the Wi-Fi cable modem and cable wall outlet. Use your hand to tighten each connector, if necessary.
  2. Check the Ethernet cable (if connected) to make sure it is properly connected to your Wi-Fi cable modem and computer.
  3. If you have cable television service, check your television to ensure your cable service is operating properly.



LED is disabled (not working)

  1. Check that all cable and power connections on your Wi-Fi cable modem are properly connected.
  2. Check that the Online and Wi-Fi LED icons on the front panel are lit up solid.
  3. Contact your service provider for assistance.


Green: No clients found (5 GHz or dual-band)
Blue: No clients found (2.4 GHz band only)

  1. If the problem continues after checking the coaxial cable and your IP address, check the Wi-Fi Security Mode setting on the Gateway Wi-Fi connection screen.
  2. If you enabled Wi-Fi security and configured a passphrase on the Wi-Fi cable modem, be sure each affected Wi-Fi client has the identical passphrase. If this does not solve the problem, check if the Wi-Fi client supports the selected Wi-Fi security method.

Power Cycle the Gateway
Power cycling the gateway is one of the easiest troubleshooting methods that may resolve connectivity issues.  It allows the SBG8300 to re-establish connection while retaining its current configuration settings. Following the steps below to power cycle the SBG8300.

  1. Shutdown the computer and switch off any connected clients.
  2. Disconnect the power cord from the AC wall outlet and wait one minute.
  3. Connect the power cord into the wall outlet.
  4. Wait until the Online, and Wi-Fi LEDs are solid Green.

NOTE: The SBG8300 Gateway takes approximately 10 minutes to fully operate after reboot.

  1. Restart the computer and client devices to check if the Internet connection is working.

Check the Cable Signal Levels
All DOCSIS cable modems require that the cable signals fall within a very specific range to be an acceptable level for the gateway to connect to the Internet.  The Downstream Power, Downstream SNR (Signal to Noise Ratio), and Upstream Power levels must be within the acceptable ranges for the SBG8300 gateway to operate properly.

  1. Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter into the address box, and press the Enter key.  The Gateway > Login page will appear.
  2. Enter admin in the Username field and enter the custom password in the Password field.
  3. Click the Login button.  The Gateway > Summary page will appear.

NOTE 1: It is recommended to use the ARRIS SURFboard® Manager App to configure the SBG8300 home network quick and easy.  The ARRIS SURFboard® Manager app is available on both App Store and Google Play store at no charge. 

NOTE 2: It is required to register an ARRIS account with an email address and password when setting up the ARRIS SURFboard® Manager app with the SBG8300.  When accessing the Web Manager after the ARRIS SURFboard® Manager app setup, the Login page will ask for an email address and password.  Enter the registered email address and password to log in.




  1. On the left-hand menu, click the Connection tab, then click the WAN link on the sub-menu.  The Gateway > Connection > WAN page will appear.



  2. In the Downstream QAM section, verify Power levels are within the acceptable range of -15 dBmV to +15 dBmV for each downstream channel. 



  3. In the Downstream QAM section, identify the Modulation and Power to verify SNR levels are within the acceptable range for each downstream channel. 

Downstream Signal To Noise Ratio (SNR)



Acceptable SNR



-15 to 15 dBmV

23.5 dB or greater



-6 to 15 dBmv

30 dB or greater


-15 to -6 dBmV

33 dB or greater

  1. finn111_3-1589464700484.png


  2. In the Upstream QAM section, identify the number of IndexChannel Type, and Symbolic Rate to verify the Power levels are within the acceptable range for each upstream channel. 

Upstream Transmit Power Level


Channel Type

Symbol Rate

Acceptable US Power Level



1280 Ksym/sec

+61 dBmV to 45 dBmV

2560 Ksym/sec

+58 dBmV to 45 dBmV

5120 Ksym/sec

+57 dBmV to 45 dBmV



1280 Ksym/sec

+58 dBmV to 45 dBmV

2560 Ksym/sec

+55 dBmV to 45 dBmV

5120 Ksym/sec

+54 dBmV to 45 dBmV

Three or more


1280 Ksym/sec

+55 dBmV to 45 dBmV

2560 Ksym/sec

+52 dBmV to 45 dBmV

5120 Ksym/sec

+51 dBmV to 45 dBmV

  1. finn111_4-1589464700490.jpeg


  2. Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power.

NOTE: If either of the signal levels are outside of the acceptable range, power cycle or factory reset the modem.  Factory resetting the modem will eliminate any customized settings.

  1. Contact the cable provider to adjust the signal levels to the acceptable level range.

Reset to Factory Defaults
Resetting the SBG8300 to the factory default settings should be used as the last resort.  This troubleshooting method resets all of the settings to the factory default state, clearing all previous connectivity configuration set by the cable provider and erases all custom configurations setup by the user.  

  1. Carefully insert a paper clip or small object into the reset button and press into it.
  2. Hold down the Reset button for at least 10 seconds and release it. The SBG8300 will then reboot, once the LEDs flash the SBG8300 has finished rebooting and will be configured with the default settings.

    NOTE: The SBG8300 Gateway takes approximately 10 minutes to fully operate after reboot.



  1. Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter into the address box, and press the Enter key.  The Gateway > Home Network Wizard - Step 1 page will appear.
  2. Enter a new password in the New Password field and re-enter the new password in the Re-Enter New Password field. 

    Password Requirements:
    • Minimum of 8 characters 
    • At least one uppercase alpha character 
    • At least 1 number
    • One of ~ ! @ # $ % ^ * (  ) - _ = + [ ] { } | ; : , . / ?
  3. Re-enter the new password in the Re-Enter New Password field.
  4. Enter the four-digit CAPTCHA code in the Type CAPTCHA Here field.
  5. Click the Next Step button.  The Gateway > Home Network Wizard - Step 2 page will appear.  



    NOTE: To use the default Wi-Fi credentials, click the Next Step button to skip this section. 
  6. Enter a new wireless network name in the Wi-Fi Network Name (2.4 Ghz) and the Wi-Fi Network Name (5 GHz) fields.
  7. Leave the Encryption Method (2.4 GHz) and the Encryption Method (5 GHz) fields at default (Recommended).
  8. Enter a new wireless password in the Network Password (2.4 GHz) and Network Password (5 GHz) fields.  
  9. Click the Next Step button.  The Gateway > Home Network Wizard - Step 3 page will appear.



  10. Leave the Time Zone Selection option at default (Automatic), then click the Finish button.  The Gateway > Login page will appear. 



  11. Enter admin in the Username field and the custom password in the Password field.
  12. Click the Login button to access the SBG8300 Web Manager.





  1. Reconnect the computer and any other client devices to the SBG8300 network.  Try accessing or any other website to verify if there is a working Internet connection.
  2. If the Internet connection is not re-established please contact ARRIS Technical Support Center at 1-877-466-864 or the ISP directly.


Frequent Visitor

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

Here is the link to the Arris Trouble Shooting Guide.


I agree that the problem is the power level from Xfinity.

New Poster

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

I have the exact same problem with the exact same modem. The easiest way to get them to fix your problem is to chat with the robot in support, then type "I would like to speak with an agent" twice. Then you will be transfered to a live agent, and you should copy and paste your problem. Hopefully you fill find an agent who sends tech support to your house for cable signal readjustment.


Edit: after a comcast visit, I was provided a splitter to higher the power level to 48-49, and for about 2 days everything was fine, but then then the internet went back to disconnecting randomly

Frequent Visitor

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

I reached the Done With it point being the Monkey in the middle with Arris and Comcast pointing fingers at each other and leaveing me with disconnects and Router resets every 20 minutes or so. So I ordered the following product. 2 Port HDTV Amplifier for Cable TV Antenna Signal Booster CATV Multimedia Drop Amp with Active Retur...I will see if this resolves the problem and report back. I wont have it for a few days.

Frequent Visitor

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

I got a second SBG8300 and it's doing the exact same thing. I am sending both back for credit and getting a different model. I am getting 2 devices one a Cble modem and the second a Wireless Router. That should prevent the problem. I think this product line is defective.

Gold Problem Solver

Re: Arris SBG8300 Losing Connection Randomly and Acional Router Resets.

@finn111 wrote: ... Arris said that the QAM Upstream Power level should be between 47-49 ...

Arris began saying the this more than a year ago, and it's complete nonsense. Comcast's signal specs are the ones posted in the Connection Troubleshooting Tips Forum article, which says the Upstream Power Level at the modem should be between +35 dBmV and +50 dBmV. Also, +51 dBmV upstream is borderline too high.


The upstream power level is controlled automatically by Comcast's equipment and does not need to be above 45 dBmV. Many customers have service that works perfectly fine with upstream power levels below 45 dBmV. Some even operate with the upstream below 35 dBmV. That's because what's important is not the level at the modem, it's the level (and quality) of the modem's signal as received at Comcast. Comcast reps have no control over this, it's automatic and built into the system.