Arduino MEGA 2560 R2 getting hot in few seconds

Hello arduino tech support,

Arduino MEGA 2560 R2 getting hot in few seconds after plugging USB or AC-DC power adapter.
The microcontroller is getting hot then the heat spreading entire board. Nothing connected to board.
First , When the board connected via USB, drivers installed & board recognized by PC. Getting hot.
Next, I disconnected USB & connected power(center-positive plug) from AC-DC adapter(8.75 V). It is getting hot as usual.
Don't know what to do ?

We bought this board in South Korea. Letters on board shows "MADE IN ITALY".

(deleted)

I bought it long time ago from http://artrobot.co.kr/. Due to some other project works, i did not test it just after arrival. Now this is the problem. check out this website has dealership for Arduino official hardware.

Usually a chip that gets really hot has damaged IO pins, and is just a matter of time until total failure (unless it has already).