mines doing this after two separate installs leading me to believe A: these screens are defective or B: there's a static poin...
you can also get a DS lite that hasnt had the updates, update the cart on the DS L then see if it works on the DSi, i have had to do this several times when i inadvertently updated my dsi's
this part on putting it back together is a straight nightmare, anyone got some tips on doing this quickly? i'm just getting a flickering bottom screen which is supposed to be an upper display connection problem, not sure if i'm getting the ribbon cable in deep enough. or an up close view of it in there so i know im not forcing it