This light is often labeled as online cable sync or signal and usually has a symbol. Re initializing the internet modem.

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Modem internet light blinking. The gateway is starting. Remove the power from the modem. Here is the solution provided to help get rid of the blinking light issue. Once a network connection is established between router and isp its time to receive and send data over the adsl. Dont unplug the power or remove the battery until the update is complete. A software update is in progress.
How to fix a cable modem when the send light is blinking step 1. Power cycling your defected or dysfunctional device is essential. If not please check the light status and behavior of the arris box and the modem. The power is on. The internet light should ne on and on regular intervals it should blink. Another reason those lights are flashing all the time is that your isp may be checking to see if your connection is healthyregularly scanning online modems and gateways to make sure everything is.
In several cases the splitter might be trouble causing aspect of the connection that instead. Let the modem sit idle until the receive light starts blinking. Try to power cycle your modem and observe if you can connect to the internet. The color of the internet light on most of the routers is green. Leave the power connected to the modem. If your ethernet light doesnt light up try the following.
Verify youre using the provided yellow ethernet cable and check the connections to the computers network interface card nicethernet port and the ethernet port on the back of the motorola modem. While leaving the power connected remove the coax cable from the modem. Similar to routers most modems both cable and dsl have a light dedicated to the broadband connection.