Why the LCD screen is brightened automatically?

[hajime]

Hello. I have a MBP 2010 17". At home, I connect it to an external monitor. For the past few days, I left the machine on to backup the data. Before I went to bed, I pressed F1 several times to dim the LCD screen to a complete dark. Then, I went to bed. Few minutes later, the LCD screen was brightened by itself (really scary). This has happened several times already. Anybody knows what happened and how to fix this?

 

[daneoni]

Disable Auto Brightness in Sys Prefs.

 

[hajime]

Disable Auto Brightness in Sys Prefs.

Thanks. I will try tonight. The room was completely dark. Why the system adjusted the brightness automatically?

 

[Agent-P]

Thanks. I will try tonight. The room was completely dark. Why the system adjusted the brightness automatically?

The room may have been dark, but was the monitor on? That may affect the sensor. When I watch TV in a dark room with my MBP on my lap, the light from the TV reflects off the wall behind me and changes my screen back light according to the changes on the TV. Perhaps you're experiencing something similar.

 

[hajime]

The room may have been dark, but was the monitor on? That may affect the sensor. When I watch TV in a dark room with my MBP on my lap, the light from the TV reflects off the wall behind me and changes my screen back light according to the changes on the TV. Perhaps you're experiencing something similar.

I switched off the monitor and then reduced the brightness of the LCD screen until the screen was completely black. Then, I went to bed.

 

[alphaod]

Use Control+Shift+Eject to sleep the display.

 

[hajime]

Use Control+Shift+Eject to sleep the display.

Thanks for the info. Before I try, could you please tell me how to wake the display? By pressing any key?