How do I use the G4 touchscreen?Updated 15 days ago

The main menu shows your current timer and wavelength settings.

• Preset: choose a ready-made session (see What are the presets on my G4?). To set things up yourself instead, press back and use Settings.
• Settings: timer, wavelengths, brightness, pulse, device grouping, alarm clock, and date and time.
• Start begins your session; Pause pauses or stops it.

In NIR mode the panel can look almost off. That's normal: near-infrared light is nearly invisible.

See it in the manual: G4 Series User Manual, page 7 (master interface)