After an update system doesn't boot

[filo]

First things to try

Computer doesn’t boot, boots to a black screen, or stops at a message

While there are many potential reasons why your installation doesn’t boot to a desktop, the primary reason is that the graphics drivers haven’t loaded correctly so your login/display manager (DM) doesn’t start. This is why you get a “black screen” or stuck at an [ OK ] Started some service message. The normal reason for this is that you have the incorrect driver version for the kernel. This can happens when the mirror you are updating from is not fully synchronised, or times out, and so y…