Sounds like the SDcard. You can replace it with an 8GB or larger (max 32GB) card. Level 4 or 10 is OK. Formatted FAT32 (most new cards are formatted FAT32).
Please follow these instructions in removing the card.
If you are able to copy your card contents from the old, you can try just rebuilding from that. If you cannot read the old card, this post explains how to build a new card.