RE: XPS 15 screen becomes white
Thank you for your response, appreciate that you’ve tried all the steps mentioned and this usually happens if the LCD cable is loose you might try reseating the cable. Please click on the below link to find the Manuals for your computer and with the instructions you can try resetting the LCD cable and check the performance.
Type in the Service tag, select option Manuals and download the manuals on your computer.
Please try this step and let us know your findings.