TFT_320QVT_9341 only white screen

Try this UTFT modified: UTFT

constructor:

UTFT myGLCD(33,38,39,40,41);  // TFT ILI9341_16b

or

UTFT myGLCD(ILI9341_16,38,39,40,41);  // TFT ILI9341_16b