Make sure the monitor cable isnt warped or kinked, and plugged in correctly.
The fact you are smacking it may revolve around the magnets inside. Especially with colour tinting.
I advise against opening a monitor up, to poke at - Its usually a very bad thing.
See if your warranty is still active, if the cable checks out (try a new cable if need be). If your warranty is dead, and you dont care what happens to it at this point, before buying a new one. You may want to google for instructions on dis-assembly. That latter part isnt for the faint of heart. Again I dont suggest you take these suckers apart.
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