Geeetech

Wow! What a patch work. Mine still isn't able to get register with my SIMCard. I tried with a friend who also bought a SIM900 shield, but from another compagny. He was able to get connected to a network with my board, but he had a very bad signal strength compare to his board that wasn't damage from...

hotkebab99 wrote:Hello,
I had the same problem, I repaired my shield by doing what I say in the "SIM900 - No registration to network" topic.
And my shield is working now...

You mean your connector was soldered backward?

Hi, Sorry for this delayed answer. I was away for a while. Here's a picture of the repair I made. Has you can see, I rotated the connector 180 degree. When I received the board, the external shield of the coax pin (that is now on top of the picture) was connected to the signal trace. Because the sid...

I highly doubt that during transit someone unsolder and then re soldered the connector backward. Unfortunately, I haven't took a picture of the Board before the repair, because I wasn't sure it was the problem. The only thing I can give you is a picture of the repair I made. Next time I get a new pr...

Hi, Recently I bought one of your GSM shield, but it had a defect. When plugged, I could send AT commands to the module and communicate with the SIM900, but I could not get connected to an operator. The signal was very weak. I tried different Sim Card and operators, but it could never get connected....

Hi! I have the same exact problem, but this is what I found: After testing the conductivity of the antenna circuit, I found that the surface mount antenna connector was solder incorrectly. It was reversed and the ground was now linked to the sim900 antenna output pin. I soldered it back on the right...