How to fix writeRegister16(ILI9341_VCOMCONTROL1, 0x2B2B);

Hi I'm new for arduino and I use arduino mega 2560 with tftlcd 2.4 with shield but after I test the program this code is show.

C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\Adafruit_TFTLCD.cpp:933:0: warning: "read8" redefined
#define read8(x) x = read8fn()

In file included from C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\Adafruit_TFTLCD.cpp:17:0:
C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\pin_magic.h:230:0: note: this is the location of the previous definition
#define read8 read8inline

C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\Adafruit_TFTLCD.cpp: In member function 'void Adafruit_TFTLCD::begin(uint16_t)':
C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\pin_magic.h:533:12: warning: large integer implicitly truncated to unsigned type [-Woverflow]
lo = (d); \
^
C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\pin_magic.h:234:25: note: in expansion of macro 'writeRegister16inline'
#define writeRegister16 writeRegister16inline
^~~~~~~~~~~~~~~~~~~~~
C:\Users\Administrator\Documents\Arduino\libraries\TFTLCD-Library-1.0.3\Adafruit_TFTLCD.cpp:352:5: note: in expansion of macro 'writeRegister16'
writeRegister16(ILI9341_VCOMCONTROL1, 0x2B2B);
^~~~~~~~~~~~~~~

And it can still upload to board but the screen not show anything.
Please ask for advice.

Start with Adafruit_TFTLCD.cpp at begin() and the related macro definitions in pin_magic.h. Reproduce the warning and blank display with the stated Mega 2560, TFT shield, and ILI9341 setup, then determine whether the reported warnings explain the failure; done means a confirmed cause and documented correction or required setup.

Written by the indexing model from the issue text.