Mhhh: no screen anymore: I can see some distortion signals on screen (contrast on max) when I hit Control-Reset or Apple-Control-Reset, but I don't have any characters on the monitor, and the Disk Led stays off.

I think I'll have to open the system to check the connections.... (floppy drive, keyboard etc...)

Edit: Never mind: I've opened the system, checked the connections, used some contactspray here and there.

The system is now booting normally, and after a Command-Reset, I'm able to use the keyboard.

All good, thanks!   (relieved)