After formatting did the re-installing process work correctly ?
If yes, connect the SD card to your computer with USB connection.
Check the contence of your SD card. You should have four directories: fonts,res,save and scan.
Check the capacity of your SD card in "Properties". (righ button of your mouse) Is there still enough free space remaining? If you have an 8GO then it could be full or allmost. The device itself needs also some space to fuction, and this could be the reason why it stays blank.
In that case you need a 16GO. Copy all 4 directories from your actual SD card to your computer (one at the same time; NOT all at the same time). Format your new SD card and copy the four directories to the new one.
Try again with PC Suite updates.
Then connect SD card to your diag device.