How do I fix internal sdcard mount failure I/O error?

I have a tablet running android 4.2.2. The internal sdcard will not mount and logcat output is - failed to mount via vfat (I/O error). I used fsck_msdos and output is - ** Phase 1 - read FAT (compare skipped) Attempting to allocate 14000 KB for FAT ** Phase 2 - check cluster chains ** Phase 3 checking directories Root directory starts with free cluster Fix? yes ** Phase 4 - checking for lost files Update FATs? yes Attempting to allocate 14000 KB for FAT 1389 files, 1133632 free (2238856 clusters) ***** FILE SYSTEM WAS MODIFIED ***** But I am still getting the same error from vold. Is there anything elseI should try?