Very common issue. White screen suggests all necessary screen inputs are not connected. Most likely whilst assembling one or more of the screen input wires was knocked or the joint is not perfect and was disturbed by the movement. Reflow those GPIO and test. Also check ribbon cables. No need to pan...

Everything was working perfectly. I did some tests before putting it in the tin and everything worked fine. I was able to navigate the menus and i had picture and sound. I had trouble putting the screen in the 3d parts, my printer at school printed the pieces a little small. i finally got everything...