Netgear CM1000 modem. Ethernet LED light is the only one lite. Modem is powered up and online.

I have verified that the power cord is properly connected to the modem.  I used the power supply adapter that came with the modem.  The power source (outlet) is supplying power.  I have power failed the modem for recovery.  However, once the modem is recovered it is still only showing the Ethernet LED as lite.  The Power, Downstream, Upstream and Internet lights are all off.  Even with all the mentioned LED lights out, I still get connectivity to my Netgear NIghthawk Tri-Band WiFi Router (RAX70/AS6600).  There is no degradation in my internet connectivity or speed.  Could there be a defect in my modem that is preventing the LED lights from working properly?