Direct answer
LED meaning depends on whether the light is Power, WAN, downstream, upstream, Wi‑Fi or Ethernet. Identify label and color before rebooting or resetting.
What this covers
- Consumer gateways, modems, routers and mesh systems
- The exact condition described in the title
- Customer-accessible checks before internal repair or reset
What it does not cover
- ×A different brand, model family or similar-looking code
- ×Internal live-electrical, gas, refrigerant or sealed-system testing
- ×A guarantee that a named component has failed without isolation
Capture the exact state
ReversiblePhotograph the panel and test service on another device.
Separate the likely fault domains
ReversibleSeparate ISP signal, WAN addressing, Wi‑Fi state and Ethernet activity.
Correct only the proven, accessible condition
ReversibleReseat external cables, perform one normal restart and check provider status; avoid factory reset.
Verify once before going farther
ReversibleConfirm stable wired/wireless service and documented normal LEDs.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Exact questions
Common follow-ups
What should I record first for “Router or modem internet light is blinking, red or off”?+
Photograph the panel and test service on another device.
Does the symptom or code prove a part has failed?+
No. Separate ISP signal, WAN addressing, Wi‑Fi state and Ethernet activity.
When should I stop troubleshooting?+
Stop for hot power supplies, damaged cables, sparks, liquid or repeated loss after provider recovery.
Answer for the exact device and software version shown above.