Re: Laptop Screen is completely gray - External monitor works fine?
There is a button probably on one of the "F" keys that looks like a small picture of a computer with a white screen on the back. It would probably be in a different color than the "F" key. If you need to, hold the "Fn" (function key) and press whatever button that looks like the computer and screen behind it.
Sources: My sister's laptop.
If that does not work, try unplugging the external screen, and restarting.
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