MPU-6050 and Arduino Mega 2560 connection failed in the DMP6 example

I have a combination of Arduino Mega 2560 and MPU-6050 with GY-571 breakout board

I tried the sample sketch on arduino.cc and it gives constant values
I also tried DMP6 example by downloading the MPU6050 library from GitHub and it is giving zeros in every value except z=90.1 in YPR if sometimes the connection is succesful otherwise the connection is failed.

The connection is
VCC to 5V as it is GY-571
GND to GND
SCL to SCL 21
SDA to SDA 20
And int -D2

Please Help!!!