S33 | S34

I have an Arris S33v2 modem with an unreadable serial number.  The label on the bottom of the modem is damaged, and the serial number and MAC address have been obliterated.  I cannot login to the modem directly, as the old default password “password” doesn’t work.  Apparently the new default password is the last 8 characters of the serial number, which I cannot read.How can I solve this problem?

Hello everyone, does anyone have any idea what this means ? When i go onto my router webpage( optimum is the cable provider) and go on the downstream connection page, which shows many channels, the latest is it says i am on channel 159 and it show a lot of corrected and  uncorrectables any ideas what this means? 

We have been using the S33 for our customers and they have worked well. We received S33v3 on our latest order but they will not switch from the default 42mhz upstream limit to the mid-split 85mhz limit. Do we need a new config file and if so, how do we get it?

I try to use live chat support but warranty checker unable to find my serial. 

Hello,I have an S33v3 modem that I purchased about six months ago.Since the thunderstorms at the end of September, the modem has been losing connection on the second upstream channel and is repeatedly showing T3 and T4 errors.My ISP (Xfinity) has already replaced all cables and splitters and performed maintenance on the street line. My neighbors’ modems no longer experience T3/T4 issues—only mine continues to drop the second upstream channel every few hours.Restarting the modem temporarily resolves the problem, but the issue always returns.I suspect the modem may have been damaged during the storm. Is this possible?And if so, would this be covered under the warranty? Also I try to find my warranty info but it says unable to find my serial number.

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?

Greetings,Brand new s34 and registered, activated with Cox existing service. The WAN syncs up, no problem. I am being careful to use only one ethernet port. According to my service plan.  Now if there is no WAN, the router stays on 192.168.100.1. once the DOCSIS connection is available, the strangest thing happens: the cable modem assigns private IPv4 network from the range of 172.16.169.0/27, for example: notebook receives 172.16.169.113; gateway of 172.16.169.97; netmask is 255.255.255.224. No IPv6 assignments. My Chromebook device is assigned one address, and the gateway router is listed under another address in the same network. But there is no internet access, and the despite the lights being blue, and no longer can connect to the modem on its management interface due to change in IPV4 addresses.  So I don't understand where a DHCP assignment could come with private IP addresses. And there is basically nothing to configure

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!

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. 

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?

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.

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

blue light not coming on

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)

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

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.

The browser-gui for my S33v2 modem recommends using the SURFboard Central app.  When I download the app on my android and create and account, login, the application doesn’t tell me anything other than the model number, serial number, mac address, service provider, hardware spec, and ethernet ports. All of which I already know and have on the outside of the machine.  Even worse, it doesn’t give me any information that the browser gives me like  status, configuration, even logs, etc.  This is the only information I get;So far the app is worthless.  Am I doing something wrong; is there a link I don't know about?  What should I be expecting?

Hi. I’m being pulled around by Xfinity support telling me I cannot receive higher upload speeds since my S34 is actually S34v1 that has not been certified by Xfinity. I can find nothing relating to S34v1 versus S34. Xfinity will not provide me any documentation of their claim. Is Xfinity telling me the truth?

I am trying to set up an Arris S33 with Liveoak fiber internet service and the unit never stops blinking green. tried resetting it twice and it only goes back to flashing green. doesn’t go into pair mode or set up mode.

Multiple Level 1 Technicians have promised a callback from Melvin, Supervisor for Arris Technical Support Tier 2 Team, for several days on end. No callback has been received. Arris has been shipped back an S33 modem with power cord for a full refund per that agreed upon, but no meaningful response has been received from Arris. The Arris case number is 2412-06033.

Does Surfboard work with Verizon?

I got a new S33 modem because my old one the SB6190 seems to be failing because the internet speeds are all over the place. My router is the Orbi AX4200 or RBR750. The highest speed I was able to attain on the old modem was 750mbps but it’s usually around 500mbps. Optimum service is 1gbps.The S33 is activated with my ISP Optimum but it won’t handshake with my router AX4200. The light on the front of the modem is blue.What am I missing?Your help is appreciated.

https://1drv.ms/b/c/e9ed3dab60ad9a96/EVWUd4IjOJVOqYfwressD3YBPvYlXWRWvNyoJ6S961PWpw We are experiencing daily connectivity issues. I have attached a current event log for reference. 

Set up S33v3 per the instructions.  Called internet provider and gave MAC ID.  Light on surfboard was orange, then blinked green, then blinked green and blue.  Cannot get solid green light.  Have repowered and reset several times.  Can never get past blinking green and blue.

My Arris 34 is missing the OFDMA channel. I did have it, but then it disappeared.  Log from my Firewalla router. See attached 10/15 upload speed good at 346mbps. That’s what is supposed to happen. On the other days you can see the upload speed hits a ceiling <85 mbps. Software/Firmware from Xfinity is the latest. Xfinity tech came out and put his field test modem on my line and indeed showed 2200 down and 400 up, but this S34 modem isn’t buying it.  What can I do here?