Question:

What causes the violet or purple lines on my TV screen when connected to my cable box using Component (Y, Pb, Pr) connections, and how can I fix it?

Answer:

The violet or purple lines you see on your TV screen are most likely caused by electro-magnetic interference (EMI) from your cable box and appear if your TV is connected to your cable box using Component (Y, Pb, Pr) connections.  An example of a screen with violet or purple lines is below.

The EMI occurs because your cable box requires a “clean", undistorted flow of electricity from the wall socket, and is getting a "dirty", distorted flow instead. Many apartments and older houses have older wiring, and this causes the dirty flow of electricity which in turn generates the EMI. EMI can affect any analog signal, but because the signals transmitted by Component cables and connections carry more information; they are the most easily affected.

The easiest way to correct this issue is to switch to an HDMI cable. HDMI cables transmit a digital signal and EMI does not affect digital signals. The only other solution is to update the electrical wiring in your home.