Module does not respond!

Hi

I have connections problem to connect blynk with GSM. I use arduino mega and SIM 808 shield (GSM ). when i run the code it appears ( Module does not respond! ) . I already use the same with arduino uno with GSM 800 and its work !.

/**************************************************************
*

**************************************************************/

// Select your modem:
//#define TINY_GSM_MODEM_SIM800
#define TINY_GSM_MODEM_SIM808
// #define TINY_GSM_MODEM_SIM900
// #define TINY_GSM_MODEM_UBLOX
// #define TINY_GSM_MODEM_BG96
// #define TINY_GSM_MODEM_A6
// #define TINY_GSM_MODEM_A7
// #define TINY_GSM_MODEM_M590
// #define TINY_GSM_MODEM_ESP8266
// #define TINY_GSM_MODEM_XBEE

// Set serial for debug console (to the Serial Monitor, speed 115200)
#define SerialMon Serial

// Set serial for AT commands (to the module)
// Use Hardware Serial on Mega, Leonardo, Micro
#define SerialAT Serial1

// or Software Serial on Uno, Nano
#include <SoftwareSerial.h>
SoftwareSerial SerialAT(7, 8); // RX, TX

#define TINY_GSM_DEBUG SerialMon

#include <TinyGsmClient.h>

// Module baud rate
uint32_t rate = 0; // Set to 0 for Auto-Detect

void setup() {
// Set console baud rate
SerialMon.begin(115200);
delay(3000);
}

void loop() {

if (!rate) {
rate = TinyGsmAutoBaud(SerialAT);
}

if (!rate) {
SerialMon.println(F(“"));
SerialMon.println(F(" Module does not respond!"));
SerialMon.println(F(" Check your Serial wiring"));
SerialMon.println(F(" Check the module is correctly powered and turned on"));
SerialMon.println(F("
”));
delay(30000L);
return;
}

SerialAT.begin(rate);

// Access AT commands from Serial Monitor
SerialMon.println(F(“"));
SerialMon.println(F(" You can now send AT commands"));
SerialMon.println(F(" Enter “AT” (without quotes), and you should see “OK”"));
SerialMon.println(F(" If it doesn’t work, select “Both NL & CR” in Serial Monitor"));
SerialMon.println(F("
”));

while(true) {
if (SerialAT.available()) {
SerialMon.write(SerialAT.read());
}
if (SerialMon.available()) {
SerialAT.write(SerialMon.read());
}
delay(0);
}
}

@Ammar1 please edit your code (using the pencil icon at the bottom) and add triple backticks at the beginning and end of your code so that it displays correctly.
Triple backticks look like this:
```

Pete.