Yamaha RC-SREV1 Owner's Manual page 11

Adjusting the RC-SREV1 Brightness & Contrast
Both the brightness and contrast of the RC-SREV1 display can
be adjusted to suit your working environment or personal
preference.
Use the CONT control to set the display contrast.
1
Contrast adjusts the balance between pixels that are on and
those that are off.
Use the BRIGHT control to set the display brightness.
2
Brightness adjusts the strength of the display's backlight.
Adjusting the RC-SREV1 Brightness & Contrast
9
LCD
BRIGHT CONT
RC-SREV1—Owner's Manual