With the screen assembly, the display is controlled by the LCD cable which is one of the cables protruding from the top of the screen. If this is to get damaged at all during the repair, then the display will cease to work with that screen assembly or even display lines depending on the damage. Although the cable is a ‘flex’ cable, the degree of flexibility is limited and so small creases, tears and bends can occur which is enough to damage the part.
However, it is best to reopen the device and just make sure that the flex cables were all properly connected and just inspect for any damages. As our warranty policy states, once the part has been tampered with, returns are no longer eligible. All parts should be inspected prior to the repair to ensure the part is not damaged beforehand. Due to the nature of the issue though, we have a 25% off coupon code that can be offered to hopefully help with the financial aspect of the situation. Please reach out to WPAUS support at email@example.com where you should send possible photographs of the cable as well as a name, order number and brief description.