Summary: Comcast offers a prepaid “Xfinity NOW” service with unlimited data and a free Arris TG1682P modem. The NOW signup is hidden when you have normal Xfinity, but can be accessed by scheduling a future cancellation. A reversible hardware mod to disable the modem’s WiFi radios involves connecting Pin 1 on the TPS54328 chip to ground. The idle power consumption drops and Ethernet connection remains steady. However, be cautious of potential overloading of digital outputs and the Intel Puma 6 chipset’s history of latency/jitter problems. Visit author’s link for more details, including a disassembly video.
https://gist.github.com/pmarks-net/af40dba69272806c1ec9cbe71429d2e7