There are two technologies predominantly is use in projectors today--Liquid Crystal Display (LCD) and Digital Light Processing (DLP). One of the primary advantages of DLP over LCD is that the DLP projector can handle dust better. LCD projectors require filters to keep dust out and that can add to maintenance. DLP was developed in 1987 by Texas Instruments and DLP projectors are now found in some mobile phones too. Before calling for service, check a few things.
Check to make sure the power cord is plugged in and the main power switch is turned on if the projector—including the fan, doesn’t operate at all.
Make sure the lens cap isn’t on the lens if there’s no image on the screen.
Check to see whether there is an image source connected to the projector and that the correct source is selected on the remote control. Press the button marked “Input” a few times to toggle between sources and also check any cables between the source and the projector.
Focus the lens if the image appears blurred. Check for dirt on the lens and make sure the projector screen is directly in front of the screen.
Make sure the lamp failure warning light isn’t illuminated if you’ve got no image. If it is illuminated, replace the lamp following the instructions in the manual.
Replace the batteries in the remote control if the remote control doesn’t operate. Check that the polarity is correct. It will be marked. Make sure you are in range of the projector and make sure there aren’t any obstructions.
Make sure the video output setting on the PC is correctly set if the projector doesn’t show images from a PC. Right click on the desktop and make sure the laptop is set to display on two screens at once. It’s sometimes called dual display or extended desktop.