Share your experience!
I have 2 dead pixels on my 20inch screen.
One dead centre of the screen (annoying), one on the left corner....
How many are acceptable? (In my view none are the only acceptable level!)
If you mean 'How many before I get a free replacement,' the undoubtedly unpleasant answer is 5, or 3 clustered together.
Try rubbing them gently with a soft cloth, sometimes they go.
Still there....
But thanks (as always) for the tip 