Dell 4100 mp projector

so your laptop does not have a vga output at all?

Decrease the screen resolution of your computer to the minimum possible value and check.
Probably the projector does not support the resolution of the laptop. With a lower resolution it might work.

Dell projectors work best with windows operating system. Replacing the projector would still not resolve the problem since it is not compatible with Macintosh computers. I recommend that you contact Macintosh and ask if there is an available patch to resolve the issue.

This called syncronisation. try different resolutions on pc/laptop. it looks like projector does not like source's resolution.
Check the cable, and connectios!!!

there are two cables whith the monitor/lcd one for the power and the others goes to the computer

the message says that the cable is not attached to the computer properly take it out and refix it

The problem is with the computer, not the projector.
There are special function keys, generally with blue lettering along the top row of your keyboard. Find the one that looks like a double screen or says "CRT". Also locate the blue function key [FN], probably on the lower left on the keyboard.

Press, and hold, the [FN] key and press the [CRT] key to change to dual screen.... and wait for several seconds for the projector to detect it. If it still doesn't work after you have waited, press the key sequence again (there are 3 different screen settings).

1. Computer Screen only (normal)
2. Projector Screen only
3. Both Computer AND Projector screens

this is caused by your computer changing resolutions in order to display the video full screen. to decrease this, set your screen size as close as posible to the size of the video

your display settings may be off, so change settings to factory reset and you may have to drop the resolution on your computer. you may also have a bad cable, so try a different cable.

First, make sure your receiver output is 1080i. This should allow for the best picture with the component cable. If you want it to be the best, switch to the M1 digital input. Note: some 4100 mp might have problems with the M1 input.

good luck

One problem may be that you must tell the PC to send the signal to the external monitor. Usually, if you hold down the function button and hit the F5 key you will see several options on the screen. (Other laptops use different function keys. Look for the one that shows two tv screens. You want the option which shows the laptop and the external monitor.) To advance between options, you hit the F5 button again and it moves over to the next option.

My computer needs me to lower the resolution on the laptop in order to send the signal to the projector. If you also need to do that, you can do it in Control Panel, Display, and Settings, and lower the resolution on screen number 1.

Doing both of these things should work.

Also, confirm that it is finding signals by hooking it to a DVD or video and see if it finds the signal through one of the other ports.