My MY BOOK 3TB is unallocated

It starts when my power adaptor become unstable and frequently lost power… the I use different power adaptor then suddenlly my MY BOOK is unallocated, anybody experience the same any solution?  thanks 

Was the other power adapter an official power supply provided by Western Digital? If not, it is possible the hard drive was affected. Maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.

To Contact WD for Technical Support