DS Lite replacement mainboard

Hello,
I have been given a DS Lite that was dropped and now the top screen displays either multi-coloured fixed/flashing lines or a white screen, doing some searching indicates that the main board is damaged.

Other than the faulty display the DS works fine (No cracked hinges or screens, touch screen still works, GBA and single screen games such a chess and tetris are totally playable, wifi works.)
I am reluctant to send the unit to Nintendo for repair due to the cost (and i would like to get self-satisfaction from repairing the device myself :D .)
Does anyone know where i could get a replacement main board?
Has anyone else encountered a similar problem?
Should i just send the DS to Nintendo, any idea how much it would cost to repair (i am in UK and i believe that the DS Light is under a year old)?
Thanks for your help.
-Ubergamer