My newish 1TB drive had been working fine. Now it wont accept any files. It is showing in Disk utility as 220GB used but these files dont show up in finder. I tried to reformat the disk with disk utiity but this failed. I purchased Disk Warrior as this seemed to be recommended in previous posts and this failed to rebuild the disk. I have a 2TB disk that works perfectly. Not sure how to try and get the disk working again.