Gboard problem..SIM900 doesn't answer.

[GoogleCodeExporter]

hi..im really need help here.im working with gboard for many weeks before this 
but it is still doesn't work for me.this is the link for the board that I use.. 
http://imall.iteadstudio.com/wireless/gsm-gprs-and-wifi/im120411004.html..

when i uploading the program, the serial monitor always show this..

GSM Shield testing.
DB:NO RESP
DB:NO RESP
DB:NO RESP
Trying to force the baud-rate to 9600

1200
2400
4800
9600
19200
38400
57600
115200
ERROR: SIM900 doesn't answer. Check power and serial pins in GSM.cpp

status=IDLE

please help me.. 

Original issue reported on code.google.com by [email protected] on 12 Mar 2014 at 5:48