Strange Reset Behavior on Seedstudio GPRS v2.0

Products & Technology Shields
#1

hi!

i’ve a strange problem using the seedstudio gprs v2.0 shield. the first days everything worked well. but now the shield has a strange behavior.

I use the following commands:

AT
AT+CPIN=
AT+CREG?
AT+CIPMUX=0
AT+CIPSTATUS
AT+CSTT=“internet.t-mobile”,“t-mobile”,“tm”
AT+CIICR
AT+CIPSTATUS
AT+CIFSR
AT+CIPSTATUS

When I then try to start a data connection by (for example):
AT+CIPSTART=“TCP”,"",“80”

The Shield (not the arduino, only the shield) seems to reset and the two connection status leds (turn off).

I’ve tried

  1. using USB for the power
  2. using external power supply.

The problem exists in both cases. I’m using a leonardo board.

Does anyone have an idea what to do?
Thanks a lot in advance,

Chris