Does anyone know how to fix Sony Ericsson K770i screen problem?

My sons Sony Ericsson K770i phones screen started going funny, it started having wavy lines and going blank if he shook it it would work again, eventually it packed up completely, my husband bought a new screen for it and replaced it, it now comes on but the screen is just a dark blue colour, does anyone have any ideas what is up and how to fix, or is it destined for the bin?