how many burned pixels...

[zoranb]

... an Apple Cinema Display must have to so that it should be replaced?

 

[Giaguara]

Depends on the size .. if it's a new display and you have some dead pixels, call AppleCare as they should know the exact limit of allowance for pixel anomalies.

 

[macworks]

I think the threshold is somewhere around 5 or 6 dead pixels.

 

[zoranb]

5 or 6? u must be kidding!

 

[DeltaMac]

from an apple display service manual:
"A certain number of subpixel anomalies is considered acceptable, and these factors apply to all manufacturers using LCD technology—not just Apple products."
If you have a question about that, contact AppleCare for a good answer. An Apple service center should use a jeweler's loupe to accurately determine how many defects there actually are. Also makes a difference if the defect is bright or dark. Usually, a higher number of dark defects are allowed.
It's a good display until you complain about it...