Unfortunately my XPS 15 seems to be having this issue, that is especially visible when the monitor background is not pure black or white. Just setting the background to any solid green, blue, or greyish colour, makes these 2 bands of flickering white appear at 1/3 from the top and bottom.
I've seen that many XPS 15 owners are affected by this hardware problem, even some time after replacement too. It's obviously a case of poor hardware design, so my hopes of a solution are low.
In order to exclude driver/OS problems, I also booted my XPS 15 from a live USB drive with Ubuntu, with the result being exactly the same as in Windows 10.
Below are some photos of the issue using Windows 10 and Ubuntu:
I bought the laptop this year. So Dell support: what now?
Given in this case I would suggest you to perform a few troubleshooting steps,
*Check how the system per form's if an external monitor is connected. If the lines are seen then system board is faulty.
*Initiate LCD BIST(Built in self test ) by restarting the system then press the D Key on startup. During the test if the solid colours are seen with lines then its LCD faulty.
*Check how the system performs in safe mode with networking ,if the same issue is not seen then its software issue.
I performed the LCD test by holding down the D key and then simultaneously pressing the power button. Unfortunately the LCD test is too limited to be useful in this case because it only displays a few differently coloured screens at full brightness. The problem with that is that lighter bands are obfuscated by the brightness of the rest of the test screen. A better LCD test would consist of screens of various brightness and grayscale tests too. So this test unfortunately doesn't confirm or excluded anything.
Then I booted in safe mode with networking and the 2 light bands are still visible. The light bands are also visible in the BIOS configuration pages, in the Bitlocker enter key screen, and even in a different OS (as I already mentioned) when booting from a live usb stick. So a software issue is hereby excluded.
Thank you for the reply! Do advise the status of the system display when an extended monitor is connected, if the display is good on external screen then the system board which has the video card works fine.
Also the display test can be conducted by restarting the system win FN & Power button. If the colours are seen without any distortion then the LCD panel works fine.
Do reply to this post along with the service tag of the system sent via private message and the result of the test.
I connected my XPS 15 to an external monitor and no lines are visible on the external monitor. They're only visible on the XPS 15 display. I just sent you my service tag.
As for the LCD test, please see my previous post.