Hi, after watching your video I think I must have the same problem. I have just received a SIM900-EVB_V1.01_PCB and teh SIM900-TE-C_V1.02. It was interesting to read the comments regarding the PWRKEY. After finding some schematics it almost seems to me that the module is not compatible with the evb board?
pin 1 on the sim900 itself is connected to pin 17 on the pin header. PWRKEY on the evb board is connected to pin 11 on the pin header. Could you confirm if this was the case for you - or was yours simply no connected?
Best regards,
Shane