MY new XPS 15s screen broke so i had it replaced. However i'm having doubts that instead of my normal LED backlit screen I have been given an traditionally backlit screen.
How do I find out ?
LED-backlit screens and "traditional" backlit screens are difficult to distinguish, especially externally.
The easiest option isn't guaranteed, but you can look for stickers or model# information indicating the backlight type. In your case, where the backlight may have been altered, this won't be useful.
Internally the two have some differences. Firstly, if you can see the backlight itself it may be easy to tell if it is a more traditional bulb. If not, I found the following information: