Solve display light problem in Samsung Galaxy Core II with diagram in which points are traced related to display light ic. First confirm that Mobile lcd is working properly then check cellphone motherboard. If you have find some component faulty on mobile motherboard then clean motherboard with electronics cleaner and apply normal heat to dry. Some time this fault create due to water damage then cleaning motherboard is useful idea to remove any shortage on mobile motherboard. Check light track with multi meter and apply jumper if any any point is damage. Here in diagram point is traced and marked with line as shown in picture.
Try this trick your own risk we are not responsible for any lose during mobile repairing.