It could be that one of the connectors to the LCD came loose. You could check that first. If it isn't that, to make 100% sure that it is NOT the digitizer (which is located directly beneath the screen), you could hook it up to another working Note 3 and test it. The other possibility could be the motherboard. The motherboard is a little less costly to replace, especially if you were to find a secondhand one.
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It could be that one of the connectors to the LCD came loose. You could check that first. If it isn't that, to make 100% sure that it is NOT the digitizer (which is located directly beneath the screen), you could hook it up to another working Note 3 and test it. The other possibility could be the motherboard. The motherboard is a little less costly to replace, especially if you were to find a secondhand one. If you DO decide to buy a brand new digitizer, you can find them for about $130-150 if you shop around. I would NOT pay $250!
It could be that one of the connectors to the LCD came loose. You could check that first. If it isn't that, to make 100% sure that it is NOT the digitizer (which is located directly beneath the screen), you could hook it up to another working Note 3 and test it. The other possibility could be the motherboard. The motherboard is a little less costly to replace, especially if you were to find a secondhand one.