SD card fail of initializing

I have an arduino Mega and a catalex card reader which yesterday worked, but today y tried another time and the sd card where not detected, i am using the example code from arduino website for the card info. I have tried conecting the reader to the SPI ports in the middle of the board and it was not solved. Anyone has another idea of what can be failing?

#include <SPI.h>
#include <SD.h>

// set up variables using the SD utility library functions:
Sd2Card card;
SdVolume volume;
SdFile root;

// change this to match your SD shield or module;
// Arduino Ethernet shield: pin 4
// Adafruit SD shields and modules: pin 10
// Sparkfun SD shield: pin 8
const int chipSelect = 10;

void setup() {
  // Open serial communications and wait for port to open:
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only

  Serial.print("\nInitializing SD card...");

  // we'll use the initialization code from the utility libraries
  // since we're just testing if the card is working!
  if (!card.init(SPI_HALF_SPEED, chipSelect)) {
    Serial.println("initialization failed. Things to check:");
    Serial.println("* is a card inserted?");
    Serial.println("* is your wiring correct?");
    Serial.println("* did you change the chipSelect pin to match your shield or module?");
  } else {
    Serial.println("Wiring is correct and a card is present.");

  // print the type of card
  Serial.print("\nCard type: ");
  switch (card.type()) {
    case SD_CARD_TYPE_SD1:
    case SD_CARD_TYPE_SD2:

  // Now we will try to open the 'volume'/'partition' - it should be FAT16 or FAT32
  if (!volume.init(card)) {
    Serial.println("Could not find FAT16/FAT32 partition.\nMake sure you've formatted the card");

  // print the type and size of the first FAT-type volume
  uint32_t volumesize;
  Serial.print("\nVolume type is FAT");
  Serial.println(volume.fatType(), DEC);

  volumesize = volume.blocksPerCluster();    // clusters are collections of blocks
  volumesize *= volume.clusterCount();       // we'll have a lot of clusters
  volumesize *= 512;                            // SD card blocks are always 512 bytes
  Serial.print("Volume size (bytes): ");
  Serial.print("Volume size (Kbytes): ");
  volumesize /= 1024;
  Serial.print("Volume size (Mbytes): ");
  volumesize /= 1024;

  Serial.println("\nFiles found on the card (name, date and size in bytes): ");

  // list all files in the card with date and size | LS_DATE | LS_SIZE);

void loop(void) {


I had the same problems. In my case it was due to the too high frequency in connection with unshielded cables (15 cm).

Sometimes the problem was present and sometimes not. And some (rarely) data were read incorrectly. Instead of the character "a" an "ä" was read!

I have changed to the internal card reader of my Arduino MKRZero. Maybe you can use shorter cables or protect cables from interference or slow down spi speed?

I have same problem with Arduino Leonardo and SD shield (SD Card shield V4.0 - Seeed Wiki) and have been searching for almost one week finding no answer, but i can advise you to try these steps maybe they work with your hardware.

  1. Never connect the SD module to arduino if you are not sure which voltage level it works on (3.3 or 5V), if it is 3.3 and you connect it to a 5V pin of Arduino, you may burn your module or fry Sd card.
  2. Check first of all what kind of SD cards and file system your Sd module supports.
  3. Format your SD card FAT32 using SD Formatter
  4. If that did not work, try other SD cards and try to use SD cards with max 16GB.
  5. check CS pin on your SD module or shield and connect it to the same pin number on arduino.
  6. Try using SdFat library.

I hope that helps