I have the v1 GPRS shield, with an AT&T gophone sim in it, but when I power things up according to the wiki at viewtopic.php?f=24&t=2135&p=7790&hilit=sim900+does+not+find+network#p7790 .
Oddly, when powering up, I only get odd characters when powering up, nothing like "RDY
To answer the questions on the page, for the AT commands given,
AT+CSQ gives +CSQ: 14,0
AT+CREG? gives +CREG: 0,0
AT+CGREG? gives +CGREG: 0,0
AT+COPS? gives +COPS: 0
Also, poking around a bit, AT+CBAND? gives +CBAND: GSM850_MODE,ALL_BAND, and looking at AT+CBAND=?, that gives +CBAND: GSM850_MODE,ALL_BAND, which isn’t listed in either the 1.00 or 1.03 AT spec linked on the wiki page. Trying to set this to allow PCS_MODE results in ERROR.
I’m not really certain what to do at this point. Trying to list the available carriers with AT+COPS=? takes a minute to return just '+COPS: ’ and then seems to freeze, even after waiting 10 minutes. I’d love any pointers, etc, just something to get this working.