OLED i2C on a mega doesn't display anything, worked on uno

I have been working for about 10 hours on a buzzer box system for family games. I hit a snag. On the uno, once i wanted to incorporate the SD card for sound effects I noticed the memmory was too low to function. So i am switching to a mega, but on the mega, I cant get the same code to work. I am aware that the SDA and SCL ports are moved on the mega, and i have put them into 20 and 21 instead of 4 and 5. I've googled and googled, and I just cant figure out what else it is I need to change to get the SSD 1306 to recognize the difference.

In fact, if i check my serialmonitor, the program isn't even acting correctly. I'm assuming because it can't launch the display codes as it should so it doesn't progress? I dont know. I think the first problem is asking if there's some simple code I'm supposed to input thru ssd1306 or wire to let it know i've switched to 20 and 21. I am almost certain it's automatically using the other ports, but I didn't have to define those ports to begin with on the uno, so im not sure how to override or if i even need to.


Perhaps you might have to start by showing your code. Read the forum instructions, point 7 regarding how to show code in your posting.

#include <SPI.h> //im not sure yet
#include <Wire.h> //im not sure yet
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
//#include <SD.h> 
//#include <TMRpcm.h>

//#define SD_ChipSelectPin 9

Adafruit_SSD1306 display = Adafruit_SSD1306(128, 32, &Wire); //intiate display of type: Adafruit_SSD1306

//definitions for colors
//#define BLACK 0x0000
//#define WHITE 0xFFFF

//File myFile;
//TMRpcm tmr; 
const int SelectButtonPin = 2;
const int SDCS = 10;
const int speaker = 9;


void setup() {
 // tmr.speakerPin=9;
/* if(!SD.begin(SDCS))
  Serial.println("SD fail");
 pinMode(2, INPUT); //host Green
 pinMode(3, INPUT); //host Red
 pinMode(10, OUTPUT); // CD of SD card
 pinMode(9, OUTPUT);




On uno this much will get me to the Adrafruit gfx on screen, but on mega screen never turns on.