The HPNA light is only on if a device is using that connection, usually a STB connected via coax (can be over twisted pair in rare situations like apartments). It sounds like your setup uses ethernet which would not turn on the HPNA light.
The previous scene is an excerpt from Brain on Fire: My Month of Madness, and just one of many hallucinations Susannah Cahalan experienced in 2009 during her month-long hospital stay, in which she was diagnosed with a rare neurological autoimmune disease, known as anti-NMDA receptor encephalitis.
Making the world better, one answer at a time. Maycomb's usual disease is racism. The kids don't know yet weather to be racist or not, and they don't really understand it either. Atticus is trying to raise them against the usual disease of the county so they can grow up better people.