Xfinity Modem Blinking Green Lights: Meaning & Fix
Quick Conclusion
For Xfinity modems (e.g., XB6, XB7, XB8), a blinking green light typically indicates the device is booting up, performing a firmware update, or attempting to establish a connection with the ISP network. This is a normal operational state, not a hardware failure, but if it persists beyond 10-15 minutes, it may signal a provisioning issue or network outage.
Engineer's Pro-Tip
Xfinity gateways like the XB7 have a hidden diagnostic mode: press and hold the reset button for 30 seconds until all lights flash, then release to enter a factory reset with extended logging. This can clear deep firmware glitches causing persistent blinking, but it erases custom settings, so use as a last resort.
Why is this happening?
- The modem is in the initial boot sequence after a power cycle or reset.
- A firmware update is being downloaded and installed from Comcast's backend.
- The modem is scanning and registering on the DOCSIS network for provisioning.
- A temporary ISP network congestion or maintenance is causing extended connection attempts.
Step-by-Step Fix Flow
Wait for Normal Boot Cycle Completion
Allow the modem to complete its boot process, which usually takes 5-10 minutes. Monitor the lights; a solid green light should appear once fully connected. Avoid interrupting this to prevent firmware corruption.