How to disable Dynamic Backlight Control on a XPS 13 9365

Question

Hi all, I have a XPS 13 9365 (2018) QHD and I was trying to disable the Dynamic Backlight Control, because when it is not connected to a power supply, the colors are also modified. This is not acceptable when I'm fixing color cast on a photograph. In the past, a firmware update seemed to solve the issue ('APP_PanelFW_DBC_W10X64_A01_Setup-59XRT_ZPE.exe' in 2017), as suggested in the thread 'https://www.dell.com/community/Laptops-General-Read-Only/Dell-XPS-13-9365-Adaptive-Brightness-Disable/m-p/5113795#M916583' but after another BIOS update the problem showed up again. Searching for the firmware upgrade I used in the past, I found that is now not compatible with my model. I wasn't able to find some option in the BIOS menus for disabling the DBC. Is there some solution for this? Thank you, Francesco

fabriotti · Answer

At the end, I found the following firmware update:

https://www.dell.com/support/home/it/it/itbsdt1/drivers/driversdetails?driverid=f9g6m&oscode=wt64a&productcode=xps-13-9365-2-in-1-laptop

It is in the Italian version of the site. It seems to be compatible with my model.

I had to update the graphic card driver (that was not in the Dell Assistant list of driver to be updated...) and I was able to use the tool successfully.

But now at the log in I receive an error related to ISD_Tablet.exe: "Impossibile accedere al dispositivo, al percorso o al file specificato. E' probabile che non si disponga delle autorizzazioni necessarie", i.e. it seems that the file has been deleted or I don't have the necessary authorization/power. But I'm the admin of my PC and file is there...

AltairFoo · Answer

Follow this article. I fixed my XPS 15 9570 with the regedit modification. https://forums.windowscentral.com/microsoft-surface-book/416121-auto-brightness-off-screen-still-dims.html

fabriotti · Answer

Thanks for your reply.

Start regedit and navigate to the following key: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000
Look for the following string:
"FeatureTestControl"=dword:00009240
Replace 9240 with 9250 and reboot.

I tried to follow this suggestion, but in my register I don't have FeatureTestControl at all.

I have updated the video driver, then I used the FIrmware update ("https://www.dell.com/support/home/it/it/itbsdt1/drivers/driversdetails?driverid=f9g6m&oscode=wt64a&productcode=xps-13-9365-2-in-1-laptop" in the Italian site), but I'm not 100% sure that the color cast has disappeared...

Thank you again

XPS

Was this post helpful?