External Hard Drives not recognized now by 10.5.7

I'm having the same problem in my iMac.

I have 2 external HD. One 250Gb and the other 1Tb. Both from Buffalo connected through USB 2.0.

The first one is formatted in MacOS extended journaled format; and I use it as a back up with Time Machine, and has a small FAT32 partition, so I can use it with Windows in Bootcamp.

The other one is used as storage.

Both were working just fine, but since I updated the system to OSX 10.5.7 (from 10.5.6) using the file downloaded from Apple website, the first HD simple disappeared.

It doesn't show up on Finder or Disk Utilities. It is like it wasn't connected at all. I tried changing port/disconnecting/turning off/rebooting both computer and HD, nothing helped. I did a ZAP on the PRAM, and repaired permissions, but still nothing happens.

The 1Tb HD is working just fine, but I can't use the backup one.

If I boot my computer on the Windows/bootcamp partition, the Windows can recognise the FAT23 partition on the external HD, so it's clear that the HD is working just fine, but since the 10.5.7 update the Mac OSX can't use it.

Any suggestions?

There have been several reports that Mac OS X 10.5.7 apparently triggers a firmware bug in some Buffalo external drives.

Until Buffalo releases a fix there's not much you can do except either connect your drive to another machine or do an Archive and Install and only upgrade back to 10.5.6.

Right - I didn't mean to say it was your problem as well, but the user who posted after you specified he was using a Buffalo drive.

Your enclosure could very well be suffering from the same problem - but at this point we don't know.

Hopefully the manufacturers will have something sorted out soon, as it's often the chipset vendor that actually provides the firmware used by multiple firms in their hard drive enclosures.

I confirm it's not only a make problem.
I have a Pika One external USB multimedia disc which is not recognized anymore since my upgrade.
I did everything like CAUE (repaired authorisations, Zapped on the PRAM...) The disc isn't recognized.
If I reboot on my other external disc (Silverdrive Plus) with my bootable 10.5.6, it works and mounts.
What's the problem with 10.5.7 ?
Thanks.

Just for the heck of it, please go to System Prefs, and then Startup Disk. Is your Startup Disk actually chosen there after the upgrade to 10.5.7?

It didn't occur to me this upgrade ... but a previous upgrade was giving me weird problems - until I actually chose the Startup Disk on that SysPrefs page.

After some days trying to solve the problem, I decided to go back to 10.5.6

Used the installation DVD to restore my computer with the Time Machine backup (which, ironically, was on the HD the 10.5.7 was not "seeing").

Seems odd that the 10.5.4 DVD could recognise something the 10.5.7 cannot.

I will now wait for some solution before doing the update again.

Using my old example:

Say there's a bug where the firmware calculates the answer to "2 + 3" as "5" but calculates "3 + 2" as "6."

If Apple's old drivers always asked the firmware to add "2 + 3" but the new driver asks to add "3 + 2" it's in no way Apple's responsibility to modify their code to work around the firmware bug.

But of course that also means that until the vendor fixes the firmware, your only workaround is to go back to the previous release of Mac OS X.

This is outrageous! All my Buffalo external drives are paperweights and I can't access the (important) data on them?
Surely this must be sorted out, there must be thousands and thousands of people affected?

You can buy a different external case and put the drive in that one (in another similar thread someone has already done so and reports it works fine after the swap). He also contacted the Buffalo vendor and they state they have no intention of issuing a firmware update for the USB Buffalo drives in question. They were not sold as being Mac compatible.

Nice job, Buffalo.

For what it's worth, Granite Digital makes really nice cases you can put your hard drives into if needed, and their "Emergency Drive Copy" product will allow you to connect to any bare drive via USB without having to install it into a case first:

http://www.granitedigital.com/emergencycopyusbtosataidebridgeadapter-standardkit .aspx

Hi all, I've got a Buffalo drive and am experiencing the same problem. I tried using Onyx to no avail. The drive spins up and just sits there waiting to be recognized by OS X. I wish I hadn't run the f*%king update. I had to cancel plans today etc just because I can't get my data off...:,(

I stupidly haven't run time machine for a couple of months and worry about what I might lose if I revert back to 10.5.5 although I would gain my ext HD...?

Any other ideas that don't include buying a new enclosure or other total hassle?