OSX and Windows problem

Hello all, I searched the forum but didn’t quite see my situation. I have a 1TB My Passport for Mac. I shrunk the Mac partition to 750GB and created a FAT partition in the available space in order to copy files from an older Windows based laptop I have. I connected it to the Windows machine and tried writing to the FAT partition using a 3rd party utility which failed. Now I am trying to put the device back on the Mac and it fails to mount. It still sees the drive in disk utilities and seems to know that the 750GB partition is there but will not mount it. I also see that the device name now says “WD My Passport 0748 Media” rather than “WD My Passport for Mac” which was it’s original name. Obviously the Windows utility altered that and must’ve damaged the partition tables. First Aid says that the drive is fine. I would love to get this remounted to the Mac. I had other data on the drive besides backups in the Mac partition. Any ideas how I can fix this?
Thanks

Hello,

As you mentioned, it seems the partitions have become corrupt. If you haven’t tried this yet, I recommend you to run a repair from Disk Utility “First Aid”. If the results say the drive is fine but you can’t mount it, you’ll need to reformat the drive.

However, it is always recommended to check the USB cable and different USB ports before you reformat the drive.

I also suggest you to contact one of the data recovery agencies recommended by Western Digital: