Identify whether it is a "Hardware Failure" or a "Signal Issue." The quickest way is to open the monitor's OSD menu to isolate the cause.

1. Perform the OSD Test (Crucial): Press the monitor buttons to bring up the built-in menu.

• Lines appear OVER the menu: This indicates a hardware/panel failure. Proceed to step 5.

• Lines are NOT on the menu: The monitor is healthy. The issue lies with your cable, GPU, or PC.

  
  

2. Check/Replace Video Cables: Firmly re-seat the HDMI, DisplayPort, or VGA cable. If possible, test with a known working cable.

   
   

3. Test with Another Device: Connect the monitor to a different laptop or PC to rule out graphics card (GPU) issues.

   
   

4. Reset Monitor Settings: Use the OSD menu to perform a [Memory Recall] or [All Reset].

   
   

5. Service Request: If the lines persist even on the OSD menu, please note your Serial Number (S/N) and contact ViewSonic Service Center.

Note: * Tip: If the lines flicker or change when you gently apply pressure to the bezel, it is likely physical damage to the panel.