LCD Keypad Shield - лудим, паяем, шилды починяем...

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins 
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

void setup() { 
  // set up the LCD’s number of columns and rows: 
  lcd.begin(16, 2); 
  // Print a message to the LCD. 
  lcd.setCursor(0,0); 
  lcd.print("LCD Key Shield"); 
  lcd.setCursor(0,1); 
  lcd.print("Press Key:"); 
}

void loop() { 
  int x; 
  x = analogRead (0); 
  lcd.setCursor(10,1); 
  if (x < 60) { 
    lcd.print ("Right "); 
  } 
  else if (x < 200) { 
    lcd.print ("Up    "); 
  } 
  else if (x < 400){ 
    lcd.print ("Down  "); 
  } 
  else if (x < 600){ 
    lcd.print ("Left  "); 
  } 
  else if (x < 800){ 
    lcd.print ("Select"); 
  } 
}

#define FIRST_PIN 0 // первый вывод
#define LAST_PIN 19 // последний вывод

void Test1(byte pin)
{
  if(pin < 10) Serial.print(" PIN:  ");
  else Serial.print(" PIN: ");
  Serial.print(pin);
  pinMode(pin, OUTPUT);
  digitalWrite(pin, 0);
  Serial.print("    LOW: ");
  if(!digitalRead(pin)) Serial.print("OK  ");
  else Serial.print("FAIL");
  digitalWrite(pin, 1);
  Serial.print("  HIGH: ");
  if(digitalRead(pin)) Serial.print("OK  "); 
  else Serial.print("FAIL");
  pinMode(pin, INPUT);
  Serial.print("  PULL UP: ");
  if(digitalRead(pin)) Serial.print("OK  ");
  else Serial.print("FAIL");
  digitalWrite(pin, 0);
}

void Test2(byte pin)
{
  Serial.print("     ");
  pinMode(pin, OUTPUT);
  digitalWrite(pin, 1);
  delay(5);
  if(!digitalRead(pin))Serial.println("SHORT");
  else Serial.println("OK");
  pinMode(pin, INPUT); 
  digitalWrite(pin, 0);

}

void setup() {
  Serial.begin(9600); 

  Serial.println("Test of short circuit on GND or VCC and between pins:");
  Serial.println();
  for(byte i = FIRST_PIN; i <= LAST_PIN; i++) 
  {
    for(byte j = FIRST_PIN; j <= LAST_PIN; j++) 
    {
      pinMode(j, INPUT);
      digitalWrite(j, 0);
    }
    Test1(i);

    for(byte j = FIRST_PIN; j <= LAST_PIN; j++) 
    {
      pinMode(j, OUTPUT);
      digitalWrite(j, 0);
    }
    Test2(i);
  }

  for(byte j = FIRST_PIN; j <= LAST_PIN; j++) 
  {
    pinMode(j, INPUT);
    digitalWrite(j, 0);
  }
}

void loop() {}

Test of short circuit on GND or VCC and between pins:

 PIN:  0    LOW: FAIL  HIGH: OK    PULL UP: OK       OK
 PIN:  1    LOW: OK    HIGH: FAIL  PULL UP: FAIL     SHORT
 PIN:  2    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  3    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  4    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  5    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  6    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  7    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  8    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN:  9    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 10    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 11    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 12    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 13    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 14    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 15    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 16    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 17    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 18    LOW: OK    HIGH: OK    PULL UP: OK       OK
 PIN: 19    LOW: OK    HIGH: OK    PULL UP: OK       OK