Late 2009 iMac can use 4k second monitor

My late 2009 iMac has a screen that goes dark from time to time. It’s annoying and was my major decision factor to not buy a new one when I upgraded my computer. Except for the ultrawide monitor, all of…
My late 2009 iMac has a screen that goes dark from time to time. It’s annoying and was my major decision factor to not buy a new one when I upgraded my computer. Except for the ultrawide monitor, all of…