"The screen gives a message that it can't see a signal, so that seems to be ok" Er? Is that right?
If so you have a problem with the connections to the screen, the graphics card or drivers. The latter might have been caused by the updates but without a screen you can't even get into the BIOS. I assume you don't see the BIOS when booting either? Is it onboard graphics or a seperate graphics card?
That said the fact that the CD drawers don't open as normal might indicate a different problem.