SIM900A showing Starting modem test...ERROR, no modem answer. Checking IMEI...Modem's IMEI: 0 Edit:
Solution can be found HERE

I am trying to interface Simcom SIM900A GSM (SIM900a Mini DEV Board v3.9.2) and I tryed interfacing it with Arduino UNO. I have connected as:
Pins:
SIM900A - Arduino
=================
VCC     - VDC (+5V)
GND     - GND
5VR     - Connect to Arduino TX (Pin 1)
5VT     - Connect to Arduino RX (Pin 0)

Power Supply (External):
5V 2A

Problem
When I upload sketch of:
Example &gt; GSM &gt; TestModem:

to Arduino, I got this output from Serial Monitor:

Starting modem test...ERROR, no modem answer.
Checking IMEI...Modem's IMEI: 0
Reseting Modem... Modem is functioning properly: IMEI: 0

Other info:

By supplying 5V, 2A the SIM900A Power LED ON continuesly and Signal LED blink with certain period of time which mean I am okay with signal.

I connected SIM900A and Arduino with Male to Male + Female to Female as I don't have Male to Female wires. I tested the wires with Multimeter and it's prefectly working.

I tested uploading other sketches of sending sms but not successful. Note that, I have load + free sms on SIM.

Power supply is actually Adapter (no transformer but circuit) with output of 5.1 Volts


My previous post can be checked HERE
PS:
Yesterday just for a minute I noted: Both LEDs (Power + Signal)  of SIM900A were blinking at same time. But then by restarting it gets Okay again.
Please help. I am likely to die becuase of tension.
Note:

Detailed Solution can be found Here



Excerpt:

My Pins connections were wrong, it should not be: 0 and 1 it should be 2 &amp; 3

Also SoftwareSerial.h is not working with SIM900A

Pins:

All connections should be like this:

SIM900A - Arduino
=================
VCC     - VDC (+5V)
GND     - GND
5VR     - Connect to Arduino TX (Pin 3)
5VT     - Connect to Arduino RX (Pin 2)


Details Here