There are 4 sets of open pair of pin in the iMetos 3.3 mother board (see below picture).
Power jumper: it is not needed anymore on boards with Revision B. If you connect the battery and you do not see LED lights turn on, then try to add jumper on this pins, as some of the first boards needs it.
Jumper 1: on the board it is labeled as “J1”. When you put jumper on this pins, you will be able to access terminal menu of the board with your PC.
Jumper 2: on the board it is labeled as “J2”. When you put jumper on this pins, you will be able to access the modem through terminal directly. This is intended and used only by iMetos developers.
Boot jumper: on the board it is labeled as “BOOT”. Jumper on this pins is needed when you want to manually upload new firmware to the board with PI Firmware Up-Loader application. More on this is available in the Uploading firmware page.
Jumper 1 and jumper 2 function is conditioned to the connection of the USB cable. Without cable they are ignored. This is not the case of the BOOT jumper if you forget to remove this jumper the station will not go into normal mode of operation and you will have to return to the station and fix this inconvenience manually.