Sd2Card.init() is successful vs. not successful

failure.cpp

//SD Card Library
#include <stdlib.h>
#include <stdint.h>
#include <SdFat.h>
#include <algorithm>

uint16 bufferA[40];
uint16 bufferB[40];
uint16 * incomingBuffer = bufferA;
uint16 * outgoingBuffer = bufferB;

int bufferIndex = 0;

//SD Card Variable Initialization
Sd2Card card;
SdVolume volume;
SdFile root;
SdFile file;

// Analog input pin.
const int adcPin = 1;

void setup(){
  // Declare adcPin as INPUT_ANALOG:
  pinMode(adcPin, INPUT_ANALOG);
  pinMode(BOARD_BUTTON_PIN, INPUT);
  pinMode(BOARD_LED_PIN, OUTPUT); 
  
  //Being SD Card File-Write Initialization
  SerialUSB.begin();

  SerialUSB.println("type any char to start");
  while (!SerialUSB.available());
  SerialUSB.println();
  delay(500);
  if (!card.init()) 
    SerialUSB.println("card.init failed");
  else
    SerialUSB.println("card.init passed");

  // initialize a FAT volume
  if (!volume.init(&card)) 
    SerialUSB.println("volume.init failed");
  else
    SerialUSB.println("volume.init passed");
    
  
  // open the root directory
  if (!root.openRoot(&volume)) 
    SerialUSB.println("openRoot failed");
  else
    SerialUSB.println("openRoot passed");
    
  char name[] = "data.raw";
  file.open(&root, name, O_CREAT | O_WRITE | O_APPEND); //open file
  if(!file.isOpen()) {
    SerialUSB.println("Could not open file!"); //Error if file isn't open.
    while (1) ;
  } else {
    SerialUSB.println("Writing from adc in one second...  press button (\"BUT\") to close the file! LED says it's safe to eject.");
  }
}

void loop(){
  uint16 adcValue = analogRead(adcPin);
  incomingBuffer[bufferIndex%40] = adcValue;
  
  if(bufferIndex%40 == 39) {
    // swap the buffers around
    std::swap(incomingBuffer,outgoingBuffer);
    file.write((uint8_t *)outgoingBuffer,80);
  }
  
  bufferIndex++;

  //Close File when the button gets pressed.
  if (isButtonPressed()) {
    file.close();
    toggleLED();
    while (1);
  }
}

success.cpp

//SD Card Library
#include <stdlib.h>
#include <SdFat.h>
#include <HardwareSPI.h>
#include <stdint.h>

//16.16 fixed point Library
#include <fix16.h>
#include <fixmath.h>
#include <fract32.h>
#include <uint32.h>

//These variables used for ADC conversion to voltage
float conv = 0.000806; //Conversion constant = 3.3v/4096
fix16_t v_conv;

//SD Card Variable Initialization
Sd2Card card;
SdVolume volume;
SdFile root;
SdFile file;

// Analog input pin.
const int analogInputPin = 1;


/*
 * Write CR LF to a file
 */
void writeCRLF(SdFile& f) {
  f.write((uint8_t*)"\r\n", 2);
}

/*
 * Write a string to a file
 */
void writeString(SdFile& f, char *str) {
  uint8_t n;
  for (n = 0; str[n]; n++);
  f.write((uint8_t *)str, n);
}


void setup(){
  // Declare analogInputPin as INPUT_ANALOG:
  pinMode(analogInputPin, INPUT_ANALOG);
  
  //Convert floating conversion to fix16 conversion
  v_conv = fix16_from_float(conv);
  
  
  //Being SD Card File-Write Initialization
  SerialUSB.begin();

  SerialUSB.println("type any char to start");
  while (!SerialUSB.available());
  SerialUSB.println();

  if (!card.init()) 
    SerialUSB.println("card.init failed");
  else
    SerialUSB.println("card.init passed");
//  spi.end();
  
//  spi.begin(SPI_1_125MHZ, MSBFIRST, 0);
  
  // initialize a FAT volume
  if (!volume.init(&card)) 
    SerialUSB.println("volume.init failed");
  else
    SerialUSB.println("volume.init passed");
    
  
  // open the root directory
  if (!root.openRoot(&volume)) 
    SerialUSB.println("openRoot failed");
  else
    SerialUSB.println("openRoot passed");

}

void loop(){
  
  // Read the analog input into a variable:
  int analogValue = analogRead(analogInputPin);

  fix16_t voltage = fix16_mul(fix16_from_int(analogValue), v_conv);
  conv = fix16_to_float(voltage);
  
  
  char floatstr[10];
  //sprintf(floatstr, "%f", conv);
  gcvt(conv,5,floatstr);
  

  // print the result:
  SerialUSB.println(floatstr);
  
  // create a new file
  char name[] = "data.txt";
  file.open(&root, name, O_CREAT | O_WRITE | O_APPEND); //open file
  if(!file.isOpen()) {
    SerialUSB.print("Could not open file!"); //Error if file isn't open.
    while (1) ;
  }
  SerialUSB.print("Writing to: ");
  SerialUSB.print(name);
  SerialUSB.print("\n");
  
  //Write data to file
  writeString(file, "Voltage: ");
  writeString(file, floatstr);
  writeCRLF(file);
  
  //Close File
  file.close();
  
  delay(1000);
}