ESP8266 -01 doesn't reply with anything The problem started when I tried to upload the Blink program to the module, it uploaded with no issues through Arduino but after that the blue LED didn't blink.

I searched a lot for it and found that the pin number may need to be changed.

So I uploaded this code 

int LED0 = 0;
int LED1 = 1;
int LED2 = 2;

void setup() {
  pinMode(LED0, OUTPUT); // Initialize the LED_BUILTIN pin as an output
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  Serial.print("LED_BUILTIN = ");
  Serial.print(LED_BUILTIN, DEC);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED0, LOW); // Turn the LED on (Note that LOW is the voltage level
  digitalWrite(LED1, LOW); // but actually the LED is on; this is because
  digitalWrite(LED2, LOW); // it is active low on the ESP-01)
  delay(1000); // Wait for a second
  digitalWrite(LED0, HIGH); // Turn the LED off by making the voltage HIGH
  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, HIGH);
  delay(2000); // Wait for two seconds (to demonstrate the active low LED)
}


to ensure the blinking but still nothing out.


After that I tried AT commands and no replies also.  
After that I did some searches and found that it may need to update the flash program and that's what I did. 
No sync occurs until I remove and connect the power to the module while the tool is trying to sync. Otherwise, it gives a fail.  
By removing and connecting the power to the module I was able to upload that flash,   
But I still have the same problem - no reply from the module to AT commands and the blink output is nothing.  
Finally I directly connected the TX to the 3.3 V and the blue LED is on so I figured that the problem is in the replying from the module.


Any help would be appreciated.
Hasn't the ESP8266 got different pin numbering? ie
arduino pin 2 = pin 4 on esp8266,
arduino pin 3 = pin 5 on esp8266,
and arduino pin 4 = pin 2 on esp8266? and pin 4 on esp8266 is the built-in led.
hope it helps.