What I sent Arris tech support…
I recently (December 4, 2025) replaced an Arris T25 modem with an Arris S33 modem. I like Arris products.
The T25 gave me over 6 years of continuous, uninterrupted 24/7 service and saved me a boat load of money owning my own modem instead of renting one from my ISP (Xfinity). ( Replaced an older Arris slow speed modem with the faster speed T25). The internet indicates typical useful life of modems between 5 and 8 years.
The T25 all of a sudden stopped working on December 1, 2025. The power light dimly lit but the modem would not accept or transmit data and the internet was down. I confirmed proper power was fed to the modem (12 volt from the adapter) and that the ISP was providing a proper signal. I did all the usual reboot and troubleshooting effort with no results. The new S33 modem installed without a hitch and now my internet system is functioning back to normal again – so as I suspected a busted T25 modem. During a 24 hour outage, I used my iPhone as a hotspot modem and also used the internet from a neighbor, so home office needs continued without delay. [I learned about hotspot internet backup with my iPhone as part of emergency backup plans, especially if power outage – can use phone battery power]. As an aside, all our sensitive electronic equipment, including the modem, are connected to surge protectors and emergency battery backup units.
At any rate, I am quite curious why the T25 stopped working.
I am happy to ship the T25 at my expense to Arris designated technical site in exchange for Arris to give me a report of the testing and investigation of the modem as to what the failure cause was. As an engineer, I am curious, and I suspect Arris would be equally interested in understanding a possible preventable failure by testing and analyzing the T25.
Let me know if interested and if so a shipping address and any other instructions.
Thx