designing pcb for sim900a

[dizgah]

hi every body
with using of a sim900a minum board i did a simple project & know i want to make my own pcb for that ,but i design & make more than 6 pcb & test more than 10 sim900a but none of them dosent work
power supply is same with my last minimum board(worked there) schematic is simcoms schematic .
i am really mixed up ,
module only response this characters:
can any body help please ?

 

[Nasser750gx]

This looks like the early days I had in UART, which I kept failing due to clock mistmatch of 3% with the UART signal...