Help! "This disk is unreadable by this computer"

[ed belknap]

External Firewire drive that I use routinely but inconsistently (i.e., it doesn't get spun up every time the computer is turned on, but it does get used every two weeks or so) just decided today that it doesn't exist!

Under OSX (10.3.9) it simply doesn't mount; won't show up on the desktop regardless of whether it's spun up before or after the Mac is turned on.

Under OS 9.2.2 I get the dreaded “This disk is unreadable by this computer. Do you want to initialize the disk?” dialog box. (Options: Eject or Initialize)

It worked fine two weeks ago!

And it's been so long since I've had to deal with mundane housekeeping on the Mac that I completely forget what the usual fix for this sort of thing is. Anyone? All suggestions would be greatly appreciated.

(Mac is a dual-1GHz G4 MDD)

[MIDI Life Crisis]

Mundane housekeeping? Like repairing permissions and verifying disks?

As far as OS 9, at best you are depending on peoples memories of how to troubleshoot that or you might find something by Googling it. Not hopeful. Even 10.3.9 is so far in the dust now that you would be hard pressed to get firsthand, definitive advice.

What have you tried so far and under which OS? Disk Utility? Third party disk utilities? Anything? Results?

Try another FW cable. They do deteriorate. Also, disks have a shelf life. If you've been using this one for several years now (maybe decades?) it may have simply died. It happens.

[ed belknap]

Mundane housekeeping? Like repairing permissions and verifying disks?

Hell, I don't think I've ever repaired permissions!

What have you tried so far and under which OS? Disk Utility? Third party disk utilities? Anything?

Haven't tried anything yet, just discovered this problem shortly before leaving home this morning. I have the default Apple Disk Utility that came with both OS's, and I have an OS9 version of Norton's System Utilities that I'll probably try when I get back to the Mac.

Thanks for the tip on the FireWire cable, I'll give that a shot too...although, why would the Mac know there was a drive connected (in OS9) if the cable was bad?

[mikehalloran]

Probably not the FW cable but could be.

First step: Reset the PRAM. This will reset your FW bus to its defaults. If this doesn't work...

If you bought AppleCare, you have a hardware test and TechTool on your DVD. This will determine if your FW bus is working properly. If not and you reset the PRAM, you have a motherboard problem. If not...

Fire up Disk Utility - see if it can verify/repair the drive. If it can, repair disk permissions. This is always the first step.

It appears you have a G4 tower - yes? If so, and the above doesn't work, pop the drive into one of your bays and see if it can be read now. If so and your FW bus tests good, it's the enclosure or your cable - or both.

If none of the above work, suspect the drive.

[dosuna11]

I had this problem with 9 and 10.39. I had another mac at work. I took the drive to work and it mounted. When I brought it back home. It was fine. This happened several times and was solved by this action. Hope it works for you.

[stephentayler]

I had an old drive a while ago that would only work if the unit was turned onto its front..... obviously something loose in the mechanism. Try turning it around/upside down - gently of course!!

Have another drive ready, so that in case you can get the suspect to work just once, you can duplicate the contents.

Cheers

Stephen

[ed belknap]

Well, after trying nearly everything suggested in this thread to no avail, I brought the drive in to the local Data Recovery specialists. Took them 10 seconds to confirm:

Mechanical Error (i.e., yer drive it be broked)

They generously offered to rescue all the data on it for the paltry sum of $850.

Since it's my archive drive -- which ostensibly means I already have copies of all its contents elsewhere -- I declined.

Arrgghh... But thanks for everyone's help!

[NazRat]

If your local recovery people did not do this, one thing you might want to try is to remove the drive from the enclosure and see if you can get it to work in another enclosure or internally. Some of the time it's the electronics in the enclosure that are fried/defective rather than the drive itself.

[Dan Walsh]

Some of the time it's the electronics in the enclosure that are fried/defective rather than the drive itself.

That was totally the case in one of my drives a couple weeks back.

[MIDI Life Crisis]

OK, you guys have prompted me to come clean and tell a recent story...

About a year ago I had two drives (about 1.5TB total) in a nice FW800 enclosure from OWC. The enclosure fell off a shelf from about 5' up and were 'dead.' I hadn't gotten around to pulling and testing them separately until a couple of weeks ago when I migrated from my G5 to a Mac Pro (which I LOVE BTW). Anyway, I pulled the drives from the G5for the MP and realized I had no drives in the G5. SO me thinks to meself, "Me? what the heck, try the drives in that enclosure."

You probably already know the answer... it was the power supply and the drives were just fine. I wiped them and installed a backup from Time Machine and they tested out just fine. I know there are velocity sensors and sophisticated parking mechanisms in these little guys and apparently they work fine.

So yeah, pull the drives and test them out of the enclosure, but I would hope the place the o/p brought them to would have also have done that. Then again, it all depends on how honest the guy on the other side of the counter is.

[ed belknap]

So yeah, pull the drives and test them out of the enclosure, but I would hope the place the o/p brought them to would have also have done that.

They didn't, they just hooked it up to a Mac and ran some whiz-bang test app...but I did the opposite: I put a new drive in the old enclosure, & the enclosure works fine.