I have a circuit where I am using a
SIM900 GSM/GPRS module. As per the datasheet it needs
3.4 V - 4.8 V and upto 2 A of current. I am using
LM2576. The input to the regulator is 12 V & 4.2 A and output (which is going to SIM900) is
4.175 V. I have connected leds for
STATUS LIGHT. I have connected a switch between
PWRKEY and GND to start the SIM900. Following is the schematic of regulator:
The problem I am facing is as soon as I press the switch S1 to turn on the SIM900, its netlight led starts blinking and status light led is always off. What does this means? Is the module faulty? How can I debug it?