There is a short in the system. Unless you have water damage, 90% chance it is the ribbon cable that runs from the motherboard in the lower part to the daughter board in the upper part. Either that cable isn't seated properly or it has been compromised (broke).
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There is a short in the system. Good chance you have water damage. Check the lower LCD backlight cable and connection. It is the small cable on the right under the larger video cable. The other small one is for the digitizer. There is also a good chance it is the ribbon cable that runs from the motherboard in the lower part to the daughter board in the upper part. Either that cable isn't seated properly or it has been compromised (broke).
There is a short in the system. Unless you have water damage, 90% chance it is the ribbon cable that runs from the motherboard in the lower part to the daughter board in the upper part. Either that cable isn't seated properly or it has been compromised (broke).