Modems

Front panel shows solid yellow lights indication stable connection (lights should be green/blue?), and router (ASUS) is fully connected and active (can be used with other modem). However, no internet connection available. I tried power cycling, but all lights return to solid with no connection available. 

I just bought a new monitor so I moved my modem and router to a different location, the router is working perfectly, but the modem is not. There's this solid amber/red light. Y reset it several times already. I unplugged it and plug it back to where it was at first but this is the problem, and there are this lights at the back, I really don't know much. Any help?

About 30 days ago purchased a SD8200. About every 1 or 2 days the MODEM will lock up. I can’t access it and must power cycle it to get it functioning. Event log messages concerning.27/11/2025 23:34:06    notice    CM-STATUS message sent. Event Type Code: 5; Chan ID: 1; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:81:a0:6d;CM-QOS=1.1;CM-VER=3.1;27/11/2025 23:34:04    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:81:a0:6d;CM-QOS=1.1;CM-VER=3.1;27/11/2025 23:34:04    warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:81:a0:6d;CM-QOS=1.1;CM-VER=3.1;

Hello I have an S33 that I need support on and the warranty checker can’t verify the serial number.  I need to troubleshoot some IPv6 issues I’ve been having with Spectrum. Thanks!

My SB8200 modem has stopped working. When plugged in nothing happens, no lights. We just had a storm so we unplugged it before the power went out (which it did). Now that the electricity is back and we plugged it back in it is apparently broken.Do I need to get a replacement or is there a way to fix it?

I have been connected to my S33 for some time. It got disconnected and then plugged back in. Light is steady blue as it should be but I am not able to connect to the internet. It is connected to the same router it had been and Im being told there is no available internet. 

Help

I bought a Surfboard S33V3 in Oct 2025 and installed with Breezeline with the 1 Gbps plan. The modem can only give me 80 to 200 Mpbs via cat6 wire connection. ISP asks me to enable the UPnP port on the modem. I logged into the modem admin page. I don’t see anywhere to change any settings, can only see status, event logs, etc. The web page asks me to use the Surfboard Central App and say I can configure my modem there.  I downloaded a copy of the Surfboard Central App, manually entered my MAC address and S/N. The app only allow me to see the modem mode, S/N, Mac address, and a link to the user guide. There is absolutely nothing else I can do or see on the App.  I also went to Surfboard support website and trying to find Arris support phone number or chat. It asks me to enter the model and Serial Number. After I entered the info, it tells me that it can’t find my S/N.  This is very frustrating to say the least.  Have I missed something?

My modem is making this awful high pitched sound. I have unplugged it into several different outlets and no luck. Help!!! This is super disappointing for a relatively new modem.

Been using the S33 for about a year with no problem. For the past month or so speeds have dropped to 11-12 download and upload. Status screen looks ok except for Downstream bonded Channels which are all in the -=5-7 DBmV range which I gather is high. Xfinity checked wiring outside and in and claims there’s no problem with their equipment. Partial event log follows. Is my modem toast? Is it really reaching back to 1969? Any advice appreciated. 31/12/1969 19:00:20 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=(Edited private information);CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 31/12/1969 19:00:22 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-9, 5-42MHz. 31/12/1969 19:00:25 3 No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:b2:16:6b;CM-QOS=1.

How do I change my password on an older Model # SB6183 to prevent hacking on my data plan?

1.) Just Provisioned S33v2 Cable Modem With My Network Provider, Cox2.) Now Online On My PC3.) Attempted-Login-To-Modem, Using Default Username and Password4.) Error-Message-Entering-Default-Username-and/or-Password-Cannot-Login-to-Modem-192.168.100.15.) Error-Message: “username or password error, pls check them again” Help! Thanks and best, Guenther Bedoo

My SB8200 completely died yesterday. All the lights have gone out. I tried a new outlet, power cable, and factory reset. It will not power back on. I’ve tried to get in touch with customer support, but the website won’t recognize my Serial Number to start a chat or get the phone number. My modem is still under warranty. I bought it from Amazon within 2 years and have the invoice. How can I contact customer support to get a replacement? 

My modem keeps losing connection the last two days sporadically. I have had this modem for 4 years with zero issues and all of a sudden now we cannot hold a steady connection. ISP (XFINITY) tested connection to my home and said everything looked good except modem wasn’t online.  we have changed cables and unplugged and power cycled. Do we need a new modem or any other suggestions? What’s odd is it will not work for several hours then come back and work for 8 hours then again not work. 

blue light not coming on

My modem was purchased two weeks ago, and it worked fine for few days then disconnected from WiFi signal, after restarting WiFi comes back. Checked with WiFi provider and no outage in the area, no service interruptions either. This is our second Arris modem that our first one didn’t have this issue. Requesting technical support or change the product. Thanks! 

Always get message “We were unable to locate your serial number. Please check your model number and serial number and try again. This information can be found on the label in back or on the bottom of your device.”Model: S33v2Serial: (Edited private information)

There is a similar issue on this page.  As of a couple of months ago, I could no longer access Disney+ on my TV, computer, phone.  When I try the TV App I get an error.  When I try to use a browser, I get an error all of which point to me being outside of the Disney Region (Outside of the US). After a month we were able to diagnose that if we use our phones as a hot spot and were able to access the streaming services once again.  Disney suggested a VPN may be the problem.  Which I do not have a VPN.  So then pointed to the ISP as having an issue. So we contacted our ISP which could not diagnose the issue and is pointing at my equipment.  Their reasoning was that other apps work, but Disney+ does not, Netflix freaks out sometimes. My Internet equipment, Surfboard SB8200 connected to Netgear MK63 Mesh.My ISP is Optimum (Cablevision / New York City, Long Island, New Jersey Region).My wireless carrier is T-Mobile I re

I got an S34 a few months ago to replace an older DOCSIS 3.0 Arris modem on Xfinity to get higher speeds, and this model is recommended for my address by Xfinity.   It worked fine for a few months, but then in the past couple weeks started dropping connection multiple times a day, sometimes recovering on its own, sometimes requiring a hard reboot.  The logs show a lot of connection issues: REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided ValueRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRWSYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;RCS Primary DS FailureVarious other T3 failures It runs fine often all day at max speeds, then in the evening and/or early morning it drops out with uncorrectable errors and struggles to resync with Xfinity.  Often I need to hard reboot it.  Xfinity tech was here

Hi,Does my modem need a firmware update. I've never done it.P/N:(Edited private information)S/N:(Edited private information)HFC MAC ID:     (Edited private information) 

I used my S33 v2 at a previous address and registered it with Arris at that time. It was on a Spectrum network.I’ve moved now and using the same S33, however, now on Xfinity. When I log into SURFboard Central it is still showing my Spectrum as my provider and I can get no data from the unit.How do I get this all reset? I’ve recently reset the modem which had no effect, I am assuming this issue is something with the SURFboard central app.

Recently got a refurbished SB8200.  Works great, stunning increase in speed over ethernet (50 to 170 Mbits per Speedtest.net)Less love for the brightness of the indicator LEDs.Apparently version 2 of this modem has the ability to change how the LEDs are displayed.  Sadly no LED dimmer function but having them turned of either all the time or when working normally would be appreciated.I assume I have v1 which does not have that functionality.How can I get a v2 modem? Is there away to determine by serial numbers? Maybe there is a firmware upgrade?If anyone has an answer I would appreciate it.Thanks - Jef

My SB8200 loses connection to Xfinity more and more often. It happened a couple of times during the first months, but now nearly every day.All lights are on.The modem web UI works. Performing a reboot via the UI does not help. I have to power it off/on. The signals look OK as per the Cable Signal Levels article. Thanks!

I purchased an SB 8200 off Amazon. It’s connected and was activated by optimum. It works other than I can’t get to the modem web page and when try and register it says serial number not found. I tried calling the number located in manual but it just hangs up on me. The serial number is the same on box as is on bottom of modem. What give ?

My SB6190 just suddenly and abruptly turned off. Even though it is plugged into a working wall outlet, it cannot turn on.There a warranty?