Dell M6400 Display Swap to LED RGB

I think I made this original post in the wrong place. So I moved it here. Sorry.

I am in the process of swaping out my display from the CCFL to a LED RGB display and seem to be having a little trouble.

I purchased the replacement display with a new cable which eliminates the CCFL inverter. It appears that is all I need to make this happen since no terminals are left without a connection.

The display comes on as expected when the machine is turned on. Its starts with a white screen at full bright then shows the Dell logo. Proceeds on to display the Windows 7 booting, but goes black when the login window should appear. Basically the backlighting gets turned off since I can see the login window, but not enough to work with. If I put the machine to sleep and wake it back up, I see the login as the screen is now a full bright.

Once logged in, I am not able to adjust brightness. Dimming with the FN-arrow keys or display preferences does not have any effect. Basically, nothing I do will allow me to dim the display. Please help.

I have tried all of the following:
1. Uninstall and reinstall the ATI display drivers
2. Reflashing the BIOS
3. Clearing CMOS
4. Uninstall and reinstall Dell's System Command
5. See if windows could find a better display driver (nope)

I am running Windows 7 Ultimate 64 bit and the machine has the ATI FirePro M7740.

Thanks

 

nobody has a clue

 

I believe the brightness control is part of the Dell ControlPoint system management package. Did you try reinstalling that? (You refer to Dell's System Command).

Also default backlight brightness levels for mains and battery operation can be set in the BIOS.

John

 

The Dell ControlPoint System Management is what I was refering too, sorry.

I have it set to max bright in the bios for both battery and power supply. None of that helped.

Thanks

 

Does the backlight go dimmer if you reduce the brightness setting in the BIOS. This will show whether or not the backlight control is working at the hardware level. (Tip: Put the mains and battery brightnesses to different values and see whether the brightness changes when you unplug / plug in the PSU).

Did you enable the on-screen notifications in DCP? This should show whether DCP is reading your keyboard inputs for brightness changes. Also, try changing the setting for the ambient light sensor.

John

 

I was under the impression that the lcd cover is different for the RGBLED display. Wouldn't that mean the connectors are different as the lcd is connected to the cover? Are you using the right cover for the RGBLED lcd panel?

 

I tried the brightness in the bios and nothing changes. I'm wondering if the backlight dimming is just broken. In Windows, the notification is working and shows the display being dimmed and brightened, but nothing is happening.

Your right, the cover does have different connections. I got a new cable with the display, which eliminates the original ccfl wiring and makes provisions for the LED.

All good ideas...

 

I am wondering if Samsung is the only company that makes RGB LED for the M6400, cause the tech here put edge to edge glass here and its a LGD018E, seems to be white led.

 

The first RGB-LED screen were from LG and Samsung, but due to a red spot in the corners on the LG screens Dell switched to Samsung only.

 

That's too bad, the LG is far superior IMO even with the red spot. Anyone know where I can purchase the LG from? have an actual model number or dell parts number?