How to Troubleshoot an Arris Modem 502G

By Jean Sommer

Updated September 28, 2017

Telephony modems incorporate Internet and phone service capabilities.
i cable modem image by IKO from

Troubles with the Arris 502G modem can mean you have no Internet or phone service. The Arris TM502G is a telephony modem used by several cable Internet providers for Internet and Voice over Internet Protocol (VoIP) telephone service. Knowing some basic troubleshooting can save you a call for a technician.

Lights and Cables

Check the status of the lights on the front of the modem. The power light will always be on and the “Online” light will be solid if you have connection. The “Link” and “Telephone” status might blink intermittently if connected. If they are all flashing at the same time, you may have lost sync with your Internet service provider (ISP). If they are all off, you have lost power to your modem, both electrical and battery.

Use the tip of a pencil or other non-metallic object and press into the reset hole that is located on the back of the modem between your Ethernet cable port and the port for your phone cable to reestablish sync. This will reboot the modem and allow it to attempt a fresh connection with your ISP. Unplugging this modem will not reset it in most cases, as it has a battery backup.

Ensure that your power cord is plugged both into the back of the modem and the wall securely. If you are using a power strip, double-check that it is powered on as well.

Check your cables if the lights appear stable, but you still have phone or Internet trouble.The Ethernet cord (looks like a large telephone cord) should be clicked into the port on both your computer and your Arris modem. Check that the cable cord is screwed to finger-tight.

Check that your telephone cord is inserted fully into both your phone and your modem, for troubles with your telephone. If you have only one telephone line/number, check that the cord is clicked into the “Tel 1/2” port only.

Lights and Cables Fine – No Internet

Try rebooting the entire system when the lights and cords seem to be as they should be and you still have Internet trouble.

Turn off your computer and any router or hub you attached to the modem.

Reset the modem, as in the Lights and Cables section above, and allow the lights to stabilize to their normal pattern. Note: Link light will not show a connection at this time.

Power on your router or hub and allow the lights on it to become normal again.

Turn your computer back on. Once it has restarted fully, check for an Internet connection.


For additional help, contact your service provider to troubleshoot your connection. They will usually send a technician if necessary.