Help, pulsating screen on MBP

[yoak]

Hi
I have a 2.5 classic MBP and when I have my preferences set to "Automatically adjust brightness" the screen "pulsates". It looks like it adjusts the brightness up an down all the time.
Thia only seems to happen in low light conditions.
Any idea what causes this?

EDIT:
The light in the room is obviously constant.
When I look at the System Pref window I can see the dot that you drag on the line to adjust the brightness pulsates as well!

 

[Eidorian]

There was a rash of pulsating LED backlights on the Macbook Pro last year. You might want to get it looked at.

 

[clyde2801]

Oh man, yours has the 'disco' option? Sweet!

 

[Animalk]

This often happens when the lighting conditions of the room are on the threshold of the lighting sensor (or its driver). I used to get this with my MBP when I was in a particular classroom and I had my backlight set to absolute minimum (trying to make the battery last) back when I was in College. I thought my screen lamp was kicking the bucket at first but it wasn't as it's still going very strong and I have never seen a reoccurrence as of yet.

It turns out, after consulting with a Genius about the issue, that it is simply the sensor not being able to decide on the brightness of the screen due to the lighting conditions being right on the threshold.

From what you've said, I would think that you are witnessing such an occurrence.

 

[yoak]

Animalik, sounds like the same issue I have.
I just got up and I´m in the same room, it´s still darkish, but I have a different lamp on and it´s not pulsating now.
Thanks for clearing that up.
Edorian, I will wait and see and hope that Animalik is right.
Always overly nervous with new hardware