External hard drive not recognized

[Aldebaron]

Good morning everyone,
I have my sister who formatted her hard drive recently and since her Mac no longer recognizes the external drive. She used Disk Utility.
Strangely enough it happened to me to lose an external hard drive the same way. So the question how to recognize an external hard drive that no longer appears after formatting.
Thank you in advance for any information
Have a good day

 

[Phil77354]

Have you tried disconnecting the drive, then restart the computer, then reconnect the drive?

Should recognize it and at that point you can either confirm it is properly formatted for use, or reformat if needed,

 

[Aldebaron]

Hello, I did as you said but it didn't work. But I have formatted Mac extended case sensitive. It erased everything and but it's gone up now

 

[chscag]

You shouldn't be using case sensitive. Format it HFS Extended (no case sensitive) and the scheme should be GUID.

 

[Phil77354]

You shouldn't be using case sensitive. Format it HFS Extended (no case sensitive) and the scheme should be GUID.

Just to clarify, my understanding is that HFS Extended (no case sensitive), also referred to as HFS+, is identified in Disk Utility as:

File system - Mac OS Extended (Journaled)
Partition Map - GUID Partition Map

 

[Aldebaron]

You shouldn't be using case sensitive. Format it HFS Extended (no case sensitive) and the scheme should be GUID.

Hello,
Okay I have to use HSF non sensitive case format then for my macbook pro.
Thank you