It is not necessary to rebuild a corrupt database. All corrupt databases can fixed in less than one minute.
The solution is: Open database to main screen
Copy the database but only one record(just pick a not recent record number at random; include “all”, I usually name this database “FixMMDD” (( month Day))
Open original database to mainscreen and append the FIXMMDD.dbf.
Occassionally you may have to update indexes. Very rarely are any records lost and when it happens those few records are clearly garbled.
I’ve been doing this for three years with no problems.
If you have fields that increment you’ll have to adjust that for your last valid value.
I think those files of your which seem unreadable are corrupt. Just one thing always keep in your mind that corruption can make a file unreadable or useless. And due to this file becomes inaccessible. Any corrupt or damaged file can’t be accessed until it gets fully repaired. All you need just remove the error from your DBF files and after doing this you can access those corrupt files. The data inside those files will be readable right after you repair them. You just need to consider about a software program or shall I suggest you about a tool which I have used?
Check this one: DBF Repair Kit
It will help you as it helped me. Just try its demo version http://www.dbf.repair/ to see the preview of the content of the files which are unreadable.