GSM sheild problems

Hey guys I'm trying to get the Arduino GSM shield to work with a simple mobile 2G card I purchased. I cannot for the life of me connect.

I am using an external power supply with the GSM module since the amperage should help with the connection?

I have been using a variety of pins with this prepaid card but cannot for the life of me figure out which one I need or if there is even one required.

there is not an antenna on the gsm module do I need one?

I have been trying to get the GSMscannetworks example to try to work for the longest time here.

:frowning:

/*

 GSM Scan Networks

 This example prints out the IMEI number of the modem,
 then checks to see if it's connected to a carrier. If so,
 it prints the phone number associated with the card.
 Then it scans for nearby networks and prints out their signal strengths.

 Circuit:
 * GSM shield
 * SIM card

 Created 8 Mar 2012
 by Tom Igoe, implemented by Javier Carazo
 Modified 4 Feb 2013
 by Scott Fitzgerald

 http://www.arduino.cc/en/Tutorial/GSMToolsGsmScanNetworks

 This example code is part of the public domain
 */

// libraries
#include <GSM.h>

// PIN Number
#define PINNUMBER 349292001663640

// initialize the library instance
GSM gsmAccess;     // include a 'true' parameter to enable debugging
GSMScanner scannerNetworks;
GSMModem modemTest;

// Save data variables
String IMEI = "";

// serial monitor result messages
String errortext = "ERROR";

void setup() {
  // initialize serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }

  Serial.println("GSM networks scanner");
  scannerNetworks.begin();

  // connection state
  boolean notConnected = true;

  // Start GSM shield
  // If your SIM has PIN, pass it as a parameter of begin() in quotes
  while (notConnected) {
    if (gsmAccess.begin(PINNUMBER) == GSM_READY) {
      notConnected = false;
    } else {
      Serial.println("Not connected");
      delay(1000);
    }
  }

  // get modem parameters
  // IMEI, modem unique identifier
  Serial.print("Modem IMEI: ");
  IMEI = modemTest.getIMEI();
  IMEI.replace("\n", "");
  if (IMEI != NULL) {
    Serial.println(IMEI);
  }
}

void loop() {
  // scan for existing networks, displays a list of networks
  Serial.println("Scanning available networks. May take some seconds.");
  Serial.println(scannerNetworks.readNetworks());

  // currently connected carrier
  Serial.print("Current carrier: ");
  Serial.println(scannerNetworks.getCurrentCarrier());

  // returns strength and ber
  // signal strength in 0-31 scale. 31 means power > 51dBm
  // BER is the Bit Error Rate. 0-7 scale. 99=not detectable
  Serial.print("Signal Strength: ");
  Serial.print(scannerNetworks.getSignalStrength());
  Serial.println(" [0-31]");

}

Is the external power supply also powering the Arduino board? Which Arduino board? A simple schematic would be helpful. Often times, where people use external power, they do not connect the grounds together which causes problem but without a schematic, it is only a guess.