4 x I2C devices check not work propary

what i am doing wrong.
i need at start-up a I2C check if the connection is made proparly.

  byte Respond1;                            // At startup, check if I2C Device responding
  byte Respond2;                            // At startup, check if I2C Device responding
  byte Respond3;                            // At startup, check if I2C Device responding
  byte Respond4;                            // At startup, check if I2C Device responding
void setup()
{
  Serial.begin(9600);
  lcd.begin(24, 2);                                 // Type LCD
  lcd.clear();
  Wire.begin();                                     // Wake up I2C Master. Connect pin 4 (the clock, or SCL, pin) and pin 5 (the data, or SDA, pin)
   
   lcd.setCursor(4,0);
   lcd.print("I2C Initializing");
   lcd.setCursor(0,1);
   
Wire.beginTransmission(Tuner_address_TX);
    Wire.requestFrom(Tuner_address_TX, 1);                      // request 1 bytes from Tuner_address_TX 0x60
    Respond1 = Wire.endTransmission();
  if (Respond1 == 0)
    lcd.print("");
    else
    lcd.setCursor(0,1);
    lcd.print("  I2C ERROR Tuner 0x60  ");
    
 delay(2500);
    lcd.setCursor(0,1);

Wire.beginTransmission(PCF1_BUTTON);
    Wire.requestFrom(PCF1_BUTTON, 1);                      // request 1 bytes from PCF1_BUTTON 0x3E
//    Respond2 = Wire.endTransmission();
  if (Respond2 == 1)
    lcd.print("");
    else
    lcd.setCursor(0,1);
    lcd.print(" I2C ERROR Buttons 0x3E ");

 delay(2500);
    lcd.setCursor(0,1);

Wire.beginTransmission(PCF2_LED);
    Wire.requestFrom(PCF2_LED, 1);                      // request 1 bytes from PCF2_LED 0x3D
    Respond3 = Wire.endTransmission();
  if (Respond3 == 0)
    lcd.print("");
    else
    lcd.setCursor(2,1);
    lcd.print("  I2C ERROR Led's 0x3D  ");

 delay(2500);
    lcd.setCursor(0,1);

Wire.beginTransmission(PCF3_RELAY);
    Wire.requestFrom(PCF3_RELAY, 1);                      // request 1 bytes from PCF3_RELAY 0x3B
    Respond4 = Wire.endTransmission();
  if (Respond4 == 0)
    lcd.print("");
    else
    lcd.setCursor(1,1);
    lcd.print(" I2C ERROR Relay's 0x3B ");

    delay(2500);
    lcd.setCursor(0,1);
    
    lcd.clear();
    lcd.setCursor(7,0);
    lcd.print("I2C Ready");
    
    delay(2000);
    lcd.clear();

Wire.beginTransmission(Tuner_address_TX);
Wire.requestFrom(Tuner_address_TX, 1); // request 1 bytes from Tuner_address_TX 0x60
Respond1 = Wire.endTransmission();

From here:Wire - Arduino Reference

Begin a transmission to the I2C slave device with the given address. Subsequently, queue bytes for transmission with the write() function and transmit them by calling endTransmission().

What are you transmitting?
If you just want read the byte from the slave you should just use the requestFrom() to invoke slave the byte.
Then you should use the available() and read() functions.

Respond1 = Wire.endTransmission();

This returns a boolean value
What are you receiving from it?

what is the problem? when i experimented with something similar i had an issue that any time there was a problem it just hung! and so i couldn't report anything.

also make sure that you have the right value for a resistor; especially if you have over a half meter of cable (check the spec).

we just spent an hour trying to debug an i2c (three arduinos) and found that if one was powered off, or the code was wrong everything hung and it hung on the Wire.endTransmission (which is of course when the data is transmitted).

you raise a good point though - how to debug things like this. the truth is that once you get it working you probably won't go back again; so it might not be worth the trouble to check this.

another thing we bumped into was volatile memory (volatile int). i'm not sure if you can store data in there and harvest it after a reset or not.

First things first. Get your shift key repaired. When you refer to yourself it is I, not i.

Wire.beginTransmission(PCF3_RELAY);
    Wire.requestFrom(PCF3_RELAY, 1);                      // request 1 bytes from PCF3_RELAY 0x3B
    Respond4 = Wire.endTransmission();
  if (Respond4 == 0)
    lcd.print("");
    else
    lcd.setCursor(1,1);
    lcd.print(" I2C ERROR Relay's 0x3B ");

Better read this: Gammon Forum : Electronics : Microprocessors : I2C - Two-Wire Peripheral Interface - for Arduino

If you are planning to have " I2C ERROR Relay's 0x3B " appear if there is an error, you need some more braces than you have shown.

How to use this forum

Point 10. Post in proper sentences.