Hi Phil,
Yes the defective SD card is the default RB Pi card with the log on it. I can not say it's the card's issue because it works fine on my computer, I think it just does not fit well with the slot in the Pi. But the fix is definitely use a thicker card.
I don't really understand the collection from the default wallet? Do you mean there is a default wallet created on the Raspberry Pi and there could be BTC already generated during the test? In my case cause I have never get original card boot successfully, and just created new card from downloaded image, does that mean I lost the original wallet already? And I also don't understand how to use that wallet and transfer the BTC out? Is there a wallet application on RB Pi? Or I just recover this wallet on another computer using the key pare? Thanks!
This is why I always ask people to make a backup.
Yes, a new wallet is generated the first time each new image is booted on the RPI. It then begins mining with that wallet, it's yours to keep. We test all BJ's at the factory like that, and some machines end up mining overnight, so there's sometimes a good bit of coin in there! I absolutely hate "orphaning" any BTC regardless of amount, as it's forever lost.
See if you can get that old card to boot, even if you have to take the case off the RPI and hold down the card. We've yet to see that particular problem. Maybe it's just a bent contact on your RPI's socket? A closer inspection may reveal why.
If you can get it to boot, the wallet is visible on the "Wallet" page from the web interface, and if you make a backup from the settings page, it will contain the wallet.
-Phil