Lost correct screen resolution on secondary monitor

Hello, I have a 19" widescreen LCD monitor that I was using as a secondary connected to my macbook pro. The native resolution for this monitor is 1440 x 900, which the os was detecting properly at first. Today I closed the macbook's lid while the external monitor was connected, the system went into sleep mode and when I woke it up, the 2nd monitor's resolution was reset to 800 x 600. Now 1440 x 900 is not even an option in the display settings, despite having rebooted / disconnected / reconnected the external monitor.

What do you have to do to get the correct screen resolution back?

Thanks.

tyson0016 said:

Hello, I have a 19" widescreen LCD monitor that I was using as a secondary connected to my macbook pro. The native resolution for this monitor is 1440 x 900, which the os was detecting properly at first. Today I closed the macbook's lid while the external monitor was connected, the system went into sleep mode and when I woke it up, the 2nd monitor's resolution was reset to 800 x 600. Now 1440 x 900 is not even an option in the display settings, despite having rebooted / disconnected / reconnected the external monitor.

What do you have to do to get the correct screen resolution back?

Thanks.

Click to expand...

I've found that sometimes when the "Mirrored mode" option is selected under the Display System Preferences, the system tries to choose the lower common denominator resolution that both displays can use. If you uncheck this setting, it will redetect the resolutions correctly (especially if you click "Detect Displays"). Check that option and let us know what you find out.

I've also found that if you enable the "Show displays in menu bar" option, and click on the monitor icon in the menu bar, you generally get a little bit more flexibility to force a particular resolution. It's kind of quirky, but if you fool around with it a bit, you can usually straighten it out.