54ReferenceHorizontal or diagonal lines on screen• In some cases, the computer and monitor may not be synchronized properly. To set the correct resolution for yourmonitor you should consult your operating system’s owner’s manual on how to “boot” your system up into the “safemode” and set monitor display for the desired mode (such as SVGA 800x600 Progressive).Black box appears on the screen• Captioning may be turned on and in text mode. Check the Closed-Caption Display control panel in the Channel menu.No sound, picture okay• Maybe the sound is muted. Try pressing the volume up button to restore sound.• Maybe the speakers are turned off. Check the Audio Output and Speakers control panel in the Audio menu.• If using an S-VHS component, remember to also connect the component’s L and R AUDIO OUT jacks to the TV’s L and RINPUT jacks.• Check the INT/EXT switch on the back of the monitor.Can’t select certain channel• Channel may be blocked or not approved in the Parental Controls menu.• If using a VCR, check to make sure the TV/VCR switch on the VCR is in the correct position.Turns off while playing• Electronic protection circuit may have been activated because of a power surge. Wait 30 seconds and then turn onagain. If this happens frequently, the voltage in your house may be abnormally high or low.• Maybe sleep timer is set.• Unplug. Wait five minutes. Plug in again.Noisy stereo reception• May be a weak station. Use Audio menu to choose mono sound.No picture, no sound but TV is on• Maybe the cable/air function is set to the wrong position.• Maybe a vacant channel is tuned.• If watching a VCR (connected only through antenna input), make sure your TV is tuned to channel 3 or 4—the same asthe CH3/4 switch on your VCR. Also check to make sure the TV/VCR switch on your VCR is in the correct position.