Xfinity Router Solid Yellow Light: Meaning & Fix
Quick Conclusion
A solid yellow light on an Xfinity router (typically an XB6, XB7, or XB8 gateway) indicates a boot-up or firmware update process is in progress, often due to a recent power cycle or ISP-initiated update. This is not a severe hardware failure but can signal a temporary connectivity disruption; if it persists beyond 30 minutes, it may point to a provisioning issue or network outage.
Engineer's Pro-Tip
Xfinity XB7 and XB8 gateways have a thermal management system that can cause a solid yellow light if overheated; keep the device at least 6 inches from walls and in a well-ventilated area to prevent throttling and erratic boot behavior, which is often undocumented in user manuals.
Community FixReddit
"Cellspot Troubleshooting"
Wait 48 hours for initial setup. Make sure it's directly connected to your modem if possible and your router into the cellspot's LAN port. After 48 hours if it's still not on, try t-force on twitter or facebook (links in the sidebar). They should be able to look at it's status from their end. ​ Initial setup can take ages though.
Read original threadWhy is this happening?
- The gateway is actively downloading or applying a firmware update from Comcast's backend.
- A boot-up sequence is ongoing after a power cycle or reset, with the device initializing its DOCSIS and Wi-Fi modules.
- A provisioning failure where the gateway cannot authenticate with Comcast's network, often due to incorrect configuration or signal issues.
- Thermal throttling has been triggered, causing the device to operate in a degraded state with slower boot processes.
Step-by-Step Fix Flow
Wait for the update or boot to complete
Allow the router to sit undisturbed for up to 30 minutes. During this time, avoid unplugging it, as interrupting a firmware update can cause corruption. Check the xFi app for any status messages about updates.