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LED Fault Patterns for ZyXEL 660R

Problem: Modem Off

Cause: Loss of Power
Possible Solutions:
  • Power cycle modem verifying the power button is in the on position and locking
  • Reseat AC adapter power connections to modem and outlet
  • Test to outlet in another room
  • Verify proper AC adapter is being used

Problem: Ethernet, DSL or Internet Light on Only

Cause: Modem is locked up
Possible Solutions:
  • Hard reset modem
  • Power cycle modem
  • Power cycle modem while holding reset
  • Remove AC adapter from outlet while modem power is on

Problem: Modem shows all LEDs on instantly on power up

Cause: Modem is locked up
Possible Solutions:
  • Hard reset modem
  • Power cycle modem
  • Power cycle modem while holding reset
  • Remove AC adapter from outlet while modem power is on

Problem: Red Power LED

Cause: Power source issue
Possible Solutions:
  • Bypass all surge protection and UPS systems
  • Verify use of correct AC adapter
  • Test modem in another room

Problem: Flashing Power LED

Cause: Stuck in Reboot
Possible Solutions:
  • Hard reset modem
  • Power cycle modem
  • Power cycle modem while holding reset
  • Remove AC adapter from outlet while modem power is on