Ext. HD mounting problems, please help

hi there

I have a problem with one of my external hard drives it won't mount again. It happened when I had a power cut and when I turned it on again my mac won't recognise it, Ive tried this several times but no joy.

The data on my external drive is pretty important to me so I would like to rescue it unharmed. Is there any way I can copy the data from my damaged hard drive onto another one because I have a spare one of the same capacity?

Please help
Rog

does the drive show up in disk utility?

have you tried powering up with the drive attached?

have you tried clearing your system caches with a program like onyx or mainmenu?

does it show up on other computers?

hi Eric,

The drive does show up on disk utility but not on the desktop, I have tried to power it up with the drive attached but it does not recognise it.

I have used Data rescue to scan the hard drive and the data is definetly still on it, however if I retrive it I get all the data but all muddled up and rearranged.

I think its the disk permissions that are damaged does onyx or mainmenu help in restoring them.
Rog

disk utility will, but any program on a mac would need to see the disk first.

you said that you used data rescue. so it does show up on another machine? did it connect to another mac, or something else?

I could give the EX disk a try on my freinds mac tomorrow. If it comes up on his does what does that mean then?

What format is the file system on this drive? I am guessing that it is FAT32. I say this because the fact that the drive shows up in Disk Utility suggests that the disk is *physically* OK. The fact that it doesn't mount on your desktop suggests that it is *logically* messed up - the partition table, the allocation tables, something else. As a result, I would *guess* that this drive will not show up on any other machine - I hope I am wrong though.

A journalled file system like HFS+ should be able to withstand file system allocation errors and recover - FAT32 is not so robust in this area.

Does anyone know of any utilities that can repair logical structures on hard drives? The name Disk Warrior (http://www.alsoft.com/DiskWarrior) comes to mind (thanks MHC!) but I have never used it.

just tried it on a different machine and the same thing happened it doesnt mount but it shows up on disk utilities, I take it this is bad news.

Im using a My book 300 GB eternal drive, how can I find out what format this disk is using?

When did you get this drive, and what type of computer would you have used to format it?

I *suspect* that if you simply bought it, plugged it in, and started to use it, and never consciously formatted it, it is likely FAT32. Most drives come that way - a sort of lowest common denominator.

I fear that this drive may have damaged logical structures. You need a good diagnostic routine for it. Disk Warrior, mentioned above, is the only one I am aware of, but I am sure there are more.

As a final idea, and assuming it is FAT32, can you connect it to a Windows box? There you could run Windows chkdsk.exe, which can repair FAT32 volumes, although it does tend to be somewhat hamfisted about it.