White screen on Mac desktop

Hi,

di you try a OS restaure with Cmd ⌘ + R when you take on your mac ?

Can I have more information about your Mac (Model / year) ?

Théo

Before you plow ahead with a restore, you may want to try certain troubleshooting steps first. First, try resetting the PRAM/NVRAM. This memory is designed to hold certain settings, but revisions of these settings are stored on the hard drive, so resetting them will return them to the last good state. Power off the Mac, then turn it on again. Just before the Mac sounds the startup chime, hold down the keys Option+Command+P+R. Continue holding these down until you hear the startup chime three times. If the Mac still does not start up, try a SMC reset. The SMC or System Management Controller is responsible for communicating between the operating system and the components, and when this goes bad, sometimes, the Mac will not start. Reset a desktop Mac by unplugging the Mac, then holding down the power button for fifteen seconds. Plug in the Mac again and try to boot it up. If this does not work, then try to see if there is an external disk that you could boot your Mac from to see if it is a problem with the disk.