External monitor recognized but not working (always!)

So, I have a A1286 that I connect to an external DELL2412 monitor.

Laptop has SSD installed and upgraded to 16GB RAM.

I managed to connect yesterday to the monitor just fine, worked all day. I shut down. Power on today, monitor gets recognized, screen operation led goes to blue for a sec and then it says no input.⏎
Have reset nvram [option-command-p-r], but nothing.⏎
Have changed resolution settings and other options, nada.

Will get another cable, but dont put my bet on that, as yesterday it was just fine. So what could possibly have changed since a shut down and a power on ?