Yes, after digging myself into the forums, I've found another guy with this problem, which is the polyfuse. Altough it shouldn't power off the Rams, it does, but only for a few seconds (10-15), and after that the printer could print again, for a certain ammount of time, after what it repeatedly would turn the Ramps off again. Don't know how the current exceed the normal 6 amps just for two days now, until than, everything was going fine...? D10 is for the extruder heater, that is a 40W cartridge type heater, and D9 is a fan. This is my setup for 4 months now on this printer...
Anyway, I changed the polyfuse with a normal glass fuse, 8A, hope it resolves my problems