Why is my screen blank?

Hi,

Has the phone been dropped or gotten wet at all?

Try shining a torch at an angle close to the screen to see if you can detect an image at all when the phone is on.

If you can see an image, (or even if you can’t) the phone will have to be opened to further diagnose the problem to isolate where exactly it might be, in the LCD display, the LCD display flex cable connection to the systemboard or the systemboard.

As a DIY repair all you can do is to initially check if the LCD screen flex cable connection to the systemboard is secure and if so then temporarily replace the screen assembly to see if it works OK or not .

Here’s a link to the ifixit 三星盖乐世 Note 3 显示组件更换 guide, which may be of some help.

Replacement display assemblies are available from ifixit (limited stock - click on the parts link in the guide to check what may be available for your particular model) or online. Just search for Samsung Galaxy Note 3 display assembly to get results for suppliers of the part.