500gb to toshiba external drive not recognized

[vagos1103gr]

500gb to toshiba external drive not recognized On imac 5k, on my laptop I can see it but not in imac, even on bootcamp windows 8.1. I called apple customer care we couldn't make it to recognize. I format the drive and in ntfs and exfat32. If I put usb stick on sub slot on iMac is recognized.

 

[jdphoto]

500gb to toshiba external drive not recognized On imac 5k, on my laptop I can see it but not in imac, even on bootcamp windows 8.1. I called apple customer care we couldn't make it to recognize. I format the drive and in ntfs and exfat32. If I put usb stick on sub slot on iMac is recognized.

Does it show up in Disk Utility? When you plug it in can you feel the hdd spinning up in the enclosure?

 

[vagos1103gr]

No it doesn't show up to disc utility and when I pluged in the light in on on hd and is spining