Cleaning Or Replacing The FilterThe air-filter sponge keeps the inside of the MultiSync MT1020/MT820 LCD Projector free fromdust or dirt and should be cleaned after every 100 hours of operation (more often in dusty conditions).If the filter is dirty or clogged, your projector may overheat.NOTE: Clean your filter after every 100 hours of operation.CAUTION• Turn off the LCD projector and wait for the fan to stop. Turn off the main power and unplugthe projector before replacing the filter.• Only clean the outside of the filter cover with a vacuum cleaner.• Do not attempt to operate the projector without a filter.• Your LCD projector will not operate unless the filter is installed correctly.• Do not put the LCD projector on end except to replace the filter.To clean the air-filter:1. Turn over the projector. Put the LCD projector on end so that the bottom is visible.2. Vacuum the filter through the filter cover.3. Place the projector back in a horizontal position.To replace the air-filter:1. Remove the filter panel by pushing up on the catch of the cover with a flat-head screwdriver untilyou feel it detach.2. Remove the filter and replace it.3. Reinstall the filter panel.NOTE: Do not detach the sponge from the filter cover. Do not wash the filter with soap and water.Soap and water will damage the filter membrane.Before replacing the air-filter, remove dust and dirt from the projector cabinet. Keep out dustand dirt during filter replacement.Remote Control Battery Installation1. Press firmly and slide the battery cover off.2. Remove both old batteries and install new ones (AA). Ensure that you have the batteries' polarity(+/–) aligned correctly.3. Slip the cover back over the batteries until it snaps into place.