Getting error 9 after trying to restore after drop

Was looking for information my iphone 7 plus. I dropped it 2 days ago and since then it has been stuck on the restore screen I have since then done all I can on apples helps section and nothing. I have also downloaded 3uitools to determine where it fails and I can see it only makes it to reading nand (20%). Nothing after this after some looking around I can gather the nand needs either re-balled or replaced is this true. And would the repair be successful or hit and miss