Electrical – the problem with the GSM 590e module


I have a M590e GSM module (assembled from a kit)

it is this kit in this link


I have sucessfully interfaced he module a PC and it does recognise AT commands sent through the serial port.
When the module starts up (with sim inserted) it does NOT say PBREADY. After waiting a few minutes after startup.

I type in the command (with the sim inserted of course)


I get the response


which I think means it is searching for a network.
When I take the sim card out of its holder and measure the voltage pins that supply power to the sim card (the VCC,GND pins in the sim card holder) I get a reading of 0.01v with a multimeter-is this normal?-should it be at least 1.8v here?-does the voltage increase in specific circumstances when the sim is inserted?
Im not sure, but is my module faulty?
I cant figure out what the fault is. I have been unable to connect any sim to a UK network so far-and I have tried three different sim card (all known to be working from testing in a phone).

Best Answer

This module is pulling a lot of power. I had to use a 5v/1500mA powersupply, but also I had to add a big capacitor also! I soldered a 2200µF at the input of the GSM m590 module. And don't forget to put the "BOOT" pin on ground.