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Troubleshoot your AT&T modem

Find out if your modem is defective.


Identify and troubleshoot modem issues

See if you have a bad modem

You may have a defective modem if it makes one of these sounds:
  • A loud humming noise
  • A line noise or modem connection sound when plugged into the telephone jack

Troubleshoot your modem

If you don’t have a defective modem:
  • Make sure your line filters are installed correctly and aren't defective. 
  • Turn the modem on and off. 
  • Check your modem light indicators. 
    • If your Power light doesn’t light up when the modem is plugged in or turned on, the modem may not be getting power. Try replacing the power cord first. 
    • A blinking or flashing Power light means that the modem isn’t getting consistent power. 
    • A flashing red  DSL or Sync light means your device couldn’t synchronize. Make sure your modem is connected to the phone line and all DSL filters are installed.

Modem still not working? Contact us.

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Community forums

Have questions about your DSL Internet service? Explore our community forums for answers.