APN, PIN, Login and Password

My console is not going past "Connecting GSM network...ERROR"..

#define PINNUMBER "0000"...
...
...
Serial.print("Connecting GSM network...");
if (gsmAccess.begin(PINNUMBER) != GSM_READY) {
Serial.println(errortext);
while (true);
}

I don't know why the SIM is not connecting.
*When I use some test sketches like "Pin Management " it shows
"
Change PIN example

No pin necessary.
Checking register in GSM network...ERROR"