Streetpass Mii Plaza Issue

[matt]

Hi so today I fire up my 3ds first thing in morning, like I always do, pop it into standby ready to collect the streetpass the day ahead offers.
Waiting for the train, I played a bit of smash to clear the streetsmash as I picked up a few on my journey to the station.
Then I press home menu and switch to mii plaza to clear the 10 tags.
Then it gets serious. It says preparing and get no further. I've waited 10 minutes for it and nothing, still preparing. So I assume it crashed or got stuck, so I hold down the power button because can't use home button.
Reload it up, same thing. This time I let it do it throughout my train journey and after a good hour, nothing.
So I remove and reinsert smash and the memory card.
Same issue. Can pick up streetpass just can't get into plaza.
Memory card is brand new pny 16gb class 10.
Everything else works fine. Smash was able to read sd card...
Any "ideas much appreciated

 

[JCnator]

Have you tried to switch back to your older SD card and manage to get past the preparing screen? If that's the case, it's likely a problem with the new SD card that cause the system to hang on forever. Otherwise, it could be the system itself that needs to be sent at a Nintendo Repair Center.