Here’s a solution that can be used to fix and repair Samsung Gt-S7562 Display problem issues like white screen, blue screen, blank screen, garbled and saturated screen displays.. This solution may help if having a LCD display problems and already tried to upgrade or restore the device firmware and replaced it with a new LCD module replacements but the problem still exists.
after dis assembling Mobile phone check whole board for rust carbon or water damages.clean lcd jack and mother board then apply hot air to dry it for a few mints.change lcd with new one if display is ok then fine else heck lcd jack prints value or remove it and replace with new.
else try all paths tracks and components and parts that are given in diagram above if any path is missing aplly jumpers and if parts are damaged change them.
Samsung GT-S7562 Display Light Ways Solution,Lcd Light Not Working Problem, Display Light Jumper