My dell 1201 projectors displays only in yellow

After turning on the projector, press "+" and "-" buttons on the control panel

simultaneously for 3 seconds and release the buttons when screen goes blank.

2 Press "+" and "-" buttons again to exit the diagnostic mode.

3While in Self-diagnostic mode, the screen will run a seven-color-cycle test as

following:

Red--> Green--> Blue--> White--> Watchet Blue--> Dark Green--> Yellow.

Ensure that the colors of the test pattern are correct. Contact Dell if the colors are
not displayed correctly.

Replacing the lamp module requires special considerations:

1. Turn off the projector.
2. Wait 30 minutes for the projector to cool down and then unplug it.
3. On the bottom of the projector, loosen the two screws on the lamp cover and then remove the cover.
4. Loosen the two screws on the lamp module and pull out the module.
5. Insert the new lamp module and tighten the two screws.
6. Install the cover and tighten the two screws.
7. Turn on the projector. If the lamp does not turn on after the warm-up period, try reinstalling the lamp again.
8. Press enter on the projector or on the remote control to open the on-screen menu.
9. Press the up ( ) or down ( ) arrow to select Setup and then press the right ( ) arrow.
10. Press the up ( ) or down ( ) arrow to select Reset lamp hours and then press enter .

1.After turning on the projector, press "+" and "-" buttons on the control panel
simultaneously for 3 seconds and release the buttons when screen goes blank.

2 Press "+" and "-" buttons again to exit the diagnostic mode.

3 While in Self-diagnostic mode, the screen will run a seven-color-cycle test as
following:
Red--> Green--> Blue--> White--> Watchet Blue--> Dark Green--> Yellow.

Ensure that the colors of the test pattern are correct.

Contact Dell if the colors are not displayed correctly.

The following is from page 69 of the 354-page Dell Technology Guide for the N5010

General Keyboard Shortcuts

<Fn><F8>
Displays icons representing all currently available display options (display only, external monitor or projector only, both display and projector, and so on). Highlight the desired icon to switch the display to that option


So the solution is just plug the VGA cable from the projector into the N5010 laptop's VGA port and then press <Fn><F8> (Function and F8 keys together).

That will be nothing to do with the lamp. It has a colour decoder fault.

It need color wheel and sensor to be clean

reset the settings to factory default. if that doesn't help, the colorwheel needs replacing.

try a new VGA cable

You can connect it directly with a composite cable. There would be a RCA(yellow) video output on the back of your cable TV. This is then connected to Video input(yellow) f you projector.

If your cable TV has Component output (threr RCA cable Green, Red, Blue), then these thre RCA could be connected to the similar one available on your Projector.

You could connect your sound als o thru the RCA out of Cable TV and input of Projector. But if you have a good AV Receiver or a sound system then it best suited for it, since the projector speaker is mono and only 2Watt output.
Let me know if there are any specific inputs required
The Dell 2200 mp projector has the following compatibility
:HDTV: 1080i, 720p
EDTV/480p: Yes SDTV/480i: Yes Component Video: Yes Video: Yes Digital Input: No Computers: Yes

I have found that the S-Video port has the correct colors, but the VGA port has green inplace of yellow. I believe the VGA port on the projector is the problem. I don't know how to replace the VGA port or if it can be replaced. Thanks D. James, tweezers.