For this repair: You need to mail in the Lcd screen also, for backlight testing.

If the copper pad or track between the logicboard is burned I will do my best to jump/bypass it for 20$ more additional charge.  If the main Power IC is burned, in such case it may not be repairable, it would also show other symptoms other than just backlight.  Please self diagnose and make sure your phone is fully functional except the backlight before you mail it in.