Problems with Arduino TFT LCD Screen

Hi guys!

Recently I bought Arduino TFT LCD Screen (Accessories — Arduino Official Store) and I use it with Arduino Mega.

Today I was trying to test my screen with this tutorial:http://www.tweaking4all.com/hardware/arduino/sainsmart-arduino-color-display/

Now i have problems with black lines

After that i try it with TFT library and have same problems.

Have any suggestion?

Thanks!