From the Mac Finder various key combinations allow you to perform operations that normally require a mouse, trackpad or other input device. The Option key (or Alt) ⌥ allows you to call up many hidden options not only in Finder m in many. It is so important that there are even those who wrote a volume dedicated to the “magic” of the Alt key (in French, here in PDF). Here are some useful combinations that are probably little known even to more expert users.
Quickly get details with System Information
Hold down the Option key, select the Apple menu and choose “About this Mac”: you can call up the “System Information” section on the fly with all the details on your computer
Quickly close various folders when opening subfolders
Double click on a Finder folder while holding down Option: the folder will open and any previous folder will automatically close.
Deselect a group of files
You probably all know that to select a whole set of files in a Finder folder just press Command-A; to deselect all the elements, just press Command-Option-A
Force exit of an app
By clicking on the icon of an application open in the Dock it is possible to exit and call up other options; keeping the Option key pressed, it is possible to call up the item “Forced exit”.
Open folders and subfolders in one go
By viewing a folder in the Finder in “as list” mode, you can click on the small triangle to the left of a subfolder to view the contents of this folder; clicking on the triangle while holding Option will open not only the subfolder but also any subfolders present in the selected folder. This abbreviation only works in list view.
Ignore duplicate files when copying
When copying a series of files from one destination to another in the Finder, the Finder offers the possibility to replace or keep both files with the same name. If you also press the Option key while moving, the “Ignore” item appears, you can continue copying by ignoring the single duplicate file. The “Ignore” item can be called up
Move instead of duplicate
If instead of moving, you want to duplicate a file from one folder to another in the Finder, just press Option while moving. The pointer changes as you drag the element.
Start a full-screen presentation of the selected files
By selecting a group of files (images, documents) and pressing the Option-Command-Y combination, you can view a slide show in Quick View of the selected files.
Empty the Trash without displaying the confirmation dialog
By pressing the Option-Shift-Command-Delete combination it is possible to empty the Recycle Bin without displaying the confirmation dialog.
Adjust the brightness of the display in smaller increments
By holding down the Option-Shift-Increase brightness or Option-Shift-Decrease brightness keys, you can adjust the brightness of the display in smaller increments. By adding the Ctrl key to this abbreviation it is possible to adjust the brightness of any external display, if this operation is supported.
In Case if your problem not fixed out then you should visit to Apple Service Center for best mac support.