New M6500 Discussion Thread

Not yet, but I will.

It would be nice to have confirmation that this issue is present in multiple configurations of the system, which is why I requested that other people turn off the ambient light sensor and test to see if different light sources (especially sunlight) shining on the sensor will change the color of the display.

It is conceivable that the issue is isolated to a particular setting/configuration on my machine, but I think that is highly unlikely.

Before contacting technical support I would like to have more information in order to help determine if this is a "systemic" issue or is isolated to my machine.

I suspect the Dell tech support "default" position will be that the issue is isolated to my machine. I'd rather not have them messing with my system configuration/hardware until I have a better idea of the potential cause.

Keith

 

keithsnell, could it be that the sun shining on the screen itself (and not on the ALS) produces these color differences?

 

Yes! (I don't know about Bokeh's particular situation; and I think he eventually reached a solution he was happy with.) I have noted such significant shifts in color on my system (based on the ambient light source) that it could certainly be a cause for many of the calibration issues.

(I will reiterate that I have the ambient light sensor turned "off" in BIOS and Control Point, but it is still affecting the color, even though it isn't changing the brightness.)

I'm one of the people that was very satisfied with my display calibration; however, now that I have discovered this potential color shift, the display colors will be "suspect" until I can get the issue resolved.

Keith

 

Well, it "could be," however I can provoke the (very significant) color shifts by placing the ambient sensor in the sunlight (window light), while keeping the LCD in the shade. I'm fairly certain this is a "behind the scenes" software adjustment of display colors based on the readings from the ALS.

Keith

 

Ok I will try to help you as I'm using your icc profile. (the best one, thanks for that)
Where is the light sensor exactly? As I'm not a graphist as you are, is there any picture where I could notice the difference easily?

 

I can only speculate since I don't own a 6500 (yet), but having other Dells with the light sensor, as well as a mbp, the only other solution aside from covering the sensor to keep it "consistent" as far as the complete lack of light it picks up would be to set the display to it's brightest. Not sure if that's an option or if your particular calibration wouldn't allow for that, though.

Come to think of it, I thought that the Fn key in combination with the "auto brightness" key would stop it from dynamically adjusting the display's brightness. Is that not the case?

 

Press the Windows key + R then type: services.msc Press the Enter key.


Find the Ambient Light Sensor Service, and double-click that Service. On the
general tab look at the Service Status: section at the bottom, it will say
started Or Stopped If that service is started click the stop Button then go to
the Startup type: pull down and select Disabled then click the Apply Button
& then click the Ok Button…


And do the same thing to the Control Point services.



NOTE:

When you make a change to your Services in: services.msc you should make a
note of that Service, and the states of the service before you make changes,
and the changes you make. This way if something happiness to your system,
you will know exactly where to go to fix the Problem…





I hope this helps,

 

Thank you!

OK, as it turns out, the ALS is not the culprit. (Please hang with me for just a moment here.) My new "theory" is that there is an undocumented sensor within the LCD that is responsible for sensing the "white balance" of the display and adjusting the colors accordingly. (This is also consistent with the obscure references I've read on the "dreamcolor" display, which is the same as the RGB LED display in the M6500.)

Here's how you can replicate what I am seeing. Set your display at a "mid" brightness setting (mine is at 39%, but any setting in that range will be adequate for seeing the effect I'm talking about.) Having a page open on the screen with an area of white will make the effect more visible, but you can see the change in tint with just about any light color displayed on the screen. Now place your system so that the LCD is receiving full sunlight (direct sunlight through a window will do). You should now see a distinctly greenish tint on the screen. Now place a 3x3 inch (7.62 centimeters) pad of post-it notes (or other light blocking small pad of paper) on the left side of the LCD in the location where the rubber bumper from the palm rest hits the bezel (about 2 1/2 inches down from the top left corner of the LCD). As soon as the pad blocks the "ambient" light from the sun, you should see the green tint disappear, to be replaced with the "normal" color tint of the LCD.

Try moving the pad of paper and placing it back in this location several times. Can you see the color tint change on the screen?

Keith

P.S.
the ALS location is shown in the diagram at this link; however I now don't believe the ALS is the culprit. http://forum.notebookreview.com/showpost.php?p=5703160&postcount=509

As someone with a systems engineering background, I really don't like uncontrollable variables!

 

I have one called "Adaptive Brightness" and the description is "Monitors ambient light sensors to detect changes in ambient light and adjust the display brightness. If this service is stopped or disabled, the display brightness will not adapt to lighting conditions." On my computer it's set to manual (by default) and the service is stopped. You can note that the option is enabled in my bios.

Thanks for the explanations. I will try tomorrow morning and not sure I will be able to, sunlight was not very strong these days...

Update : I was wrong, ambient light system was disabled in the bios. So if the windows service I described is in manual position or disabled, it should not activate the light sensor. Perhaps, keithsnell, it's time for you to update your bios to A02. (this could be a bug in A00 already fixed but not detailed in Dell release notes)

Note : Control Point software was never installed on my computer.

 

The ALS can be disabled in the bios, I do that on all my systems.
I did not think anyone actually used that feature?

But interesting none the less.