2.4 inch TFT touch LCD Screen Module For Arduino UNO R3 SD low price jocks

Using Arduino Displays
63

If it doesn't detect the driver don't fear. It may still be a 778x, but it is not being initialized, because the software has no idea what it is.

void setup()
{
  Serial.begin(9600);

  tft.reset();

  uint16_t identifier = tft.readID();

  
    Serial.print(F("Found LCD driver chip ID: "));
    Serial.println(identifier, HEX);
    
  tft.begin(identifier);

As you see the software reads the initializer and throws it on the init.

If there is no ID being read replace the above with:

void setup()
{
  Serial.begin(9600);

  tft.reset();
  tft.begin(0x9325);

The 0x9325 is a guess. Thats the only thing I have in my library, which you are likelly to be using. If not try one at the time as mentioned by jstarcher:

0x9325;
0x9328;
0x9341;
0x8357;
0x7575;

There's no need to edit the .cpp. All is done within the sketch.