SIM900 Quad Band GSM GPRS Shield Development Board For Arduino led of & and also network problem

I am using SIM900 Quad Band GSM GPRS Shield Development Board For Arduino. for making calls experiment. Workihng well until a week ago.
Suddenly it couldnt connect with network and also the flasing leds after few blings almost every second the turn off.
Difrent sims workin fine in a mobile phone are working. Net work antenna is very closed. Plus the power of arduino 5v i am using also 9v battery. Conections are establish according with site. I am stuck off …
Any help ?
Thank you veruy much in advance!

Chances are that your battery power has come down.
The module needs 4V 2A.
If the module is starting and turning off repeatedly, it means that its not getting enough current to connect to network. Change your battery to a fully charged one or use two batteries in parallel.
If you are using the battery used in multimeters, they cannot supply large currents needed by GSM modules. I have used them with GSM modules. They discharge very quickly.
I would advice to use a LiPo battery which are rated for larger current discharges.