Serial monitor does not send messages (mpu 6050)

Hi, I tried to use mpu 6050 acceleration sensor with Jeff Rowberg's DMP code. Compiling and uploading was successful. I surely connected pins to right places. (VCC-5V, GND-GND, SCL-A5, SDA-A4, INT-D2) I soldered the sensor, too. But when I open the serial monitor, the first line says "Initializing I2C devices...", and then nothing else is shown. I've been waiting for a long time, but nothing appeared. I've sent any letter, but the same. What can be the possible problem in this situation?
Your advices will be appreciated.

Serial Monitor does not send messages unless you send something. I guess it should be 'receive messages'.

Without seeing your code (please use code tags) it's difficult to say what can possibly be wrong or that it's expected behaviour. Also please provide a link to the Jeff Rowberg's stuff that you referred to.

I’ve used Jeff Rowberg’s DMP code and it works well. Note you have to click on the top of the serial monitor line, enter anything, then click on send…

or have you done all this?