220v?
the ramps takes 12 volts.
Ill guess you mean you plugged the 12v power supply into 220v.
The ramps takes 12v in and passes it through D1 to the Vin pin of the mega which converts it to 5v.
Or it takes 5v from USB if the 5v is not already present.
either D1 is missing (if your using > 12v on a ramps you have to remove this and provide 5v some other way)
Or the voltage regulator on the mega2560 board is blown. (this is a very common failure)
Unplug the ramps from the mega.
Flash the blink sketch to the mega and verify it works when connected to USB. remove USB and power the mega with 7-12v dc to the power input barrel connector.
If it doesn't work, its a dead regulator.
