2005 GMC Envoy Owner's Manual - Page 260

Cleaning the Video Screen Pour some isopropyl or rubbing alcohol on a clean cloth and gently wipe the video screen. Do not spray directly onto the screen and do not press too hard or too long on the video screen. Rear Seat Audio (RSA) This feature allows rear seat passengers to listen to any of the sources: radio, cassette tapes, CDs, or DVDs. However, the rear seat passengers can only control the sources that the front seat passengers are not listening to. For example, rear seat passengers may listen to and control cassette tapes, CDs, or DVDs through the headphones while the driver listens to the radio through the front speakers. The rear seat passengers have control of the volume for each set of headphones. The front seat audio controls always have priority over the RSA controls. If the front seat passengers switch the source for the main radio to a remote source, the RSA will not be able to control the source. You can operate the rear seat audio when the main radio is off. Envoy/Envoy Denali shown, Envoy XL/Envoy XL Denali similar P (Power): Press this button to turn the system on or off. The rear speakers will be muted when the power is turned on. u (Volume): Turn this knob to increase or to decrease the volume. The left volume knob controls the left headphones and the right volume knob controls the right headphones. SRCE (Source): Press this button to select a source: radio, cassette tape, CD, or DVD. The inactive tape, CD, or DVD will remain safely inside the radio for future listening. 3-124