Imac blank white screen

My IMac 27" shows five vertical stripes on a white background when I turn it on, while also showing the progress bar for starting up. After that the screen turns completely white and only shows the mouse arrow. It stays that way. The IMac is app 5 years old and uses the latest IOS. Any good ideas? Thanks a lot, Jacob

This thread is now locked and can not be replied to.

Surface Pro 5 News - release date, UK price, features, specs

Animator Emanuele Kabu’s psychedelic video is a stunning tribute to Lisbon city

Best Mac antivirus 2017