How do identify an Arduino counterfeit?

I was working on the HC-05 Bluetooth module and Arduino. How can I interface with Arduino if no proper connection is being established and the circuit is not responding to my command?

• I have coded the Arduino sketch for reply back appropriately for some specific inputs. I am sending the inputs via BlueTerm application but there is no reply from the BT module. I even tried various Arduino Sketches from various tutorials online. But there is no response from the BT module.

• Answer:

  Test in three parts (0) Check connection with Smart Phone (1) Sending data (2) Receiving data (0) Check Connection with smart phone - All this needs power to HC05. Download Blueterm from Google Play Store. On Android phone, scan the module and pair using defualt code 1234. Then use Blueterm and connect to the module. If every thing is okay, then Blueterm will show "Connected" on top left handside. If okay, move to next step. (1) Keep Blueterm on Android connected. On Arduino, write a small program. Open serial port at 9600 baud and send "hello" on serial port. Just 2 lines of code in side void setup (void). This should appear on Blueterm Screen. (2) Keep blueterm connected, On Arduino write a small program to wait for serial port data. When received reply back with same character. Little bigger program. Make sure your RXD Pin is pulled high. If in doubt write 1 to RXD pin using digitalWrite(1,HIGH). This pulls up RXD. Hope this helps, If not add your program in comments. Write minimum program lines for serial port. Skip any thing not relevent to serial port. Note - Assuming that you know Arduino syntex and how to burn arduino, the whole testing will not take more than 15 mins.