3.2" TFT LCD Shield + Display w SD Socket for Arduino Mega 2560, SD Problem

Using Arduino Project Guidance
2

What pin is the microSD card slave select pin? I think I would put it on digital pin 49.

The Mega2560 SPI data lines are:
MISO -> pin 50
MOSI -> pin 51
SCK -> pin 52

Then I would try this in setup:

if(!SD.begin(49)) Serial.println("SD fail");
else Serial.println("SD ok");