fsck.ext4 -n exited with status code 8
e2fsck 1.47.2 (1-Jan-2025)
ext2fs_open2: Superblock checksum does not match superblock
fsck.ext4: Superblock invalid, trying backup blocks...
fsck.ext4: Superblock checksum does not match superblock while trying to open /tmp/1485190970.img

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
 or
    e2fsck -b 32768 <device>