Was the Organelle ever working? did something happen before it stopped working? Is the problem intermittent, or does it happen every time you turn it on?
It could be the micro SD card, but it could also be a hardware problem.
There is some info on downloading / burning SD cards on this thread, but this is not recommended unless you know your way around the command line. We can also send you a new card to try. Please contact us for details.