New Western Digital "MyBook Premium Edition II" not mounting on firewire

what worked for me was unplug it from the computer. First put the plug into the mains, so you see the disk light up. Then plug the firewire in the back of the computer. I have OS X 10.5.3 and have no problems...

Thanks for your suggestion. Unfortunately, it did not work or me.
One thing I was doing - recently subscribed to Mozy, an off-site back-up service.
It took about 3 weeks for the initial creation of my duplicate/back-up file (230 GB.)
In that time I had a few stalls, and needed to play with file sharing preferences.
Could this have caused my troubles?
Looking at my preferences, I don't see anything unusual.

I'm having the same issue on different hardware.

WD MyBook II (500 GB) on a 2GHz G5 iMac connected via FireWire 400.

The drive was working fine through 10.5.2. Under 10.5.3 it no longer mounts via FireWire, but works fine on USB. I get "Error loading generic library" when attempting to apply the firmware update. I've tried the suggested unplug, power down, plug sequences but no luck.

I have exactly the same problem with my WD MyBook Premium Edition II - it will NOT mount through firewire, but will mount through USB. Everything worked fine on 10.5.2 until I've upgraded to 10.5.3. My HDD firmware is updated with the latest version available on WD site.

In addition, looking at System Profiler, FireWire section - when I connect the disk to FW800 port it shows "unknown device", and when I connect it to FW400 port, it detects the device properly as "My Book".

I've had this hard drive connected to my FW800 for the last couple of months and it worked seamlessly - until the point where I've upgraded to 10.5.3... The drive will now work only though the USB connection.

Any ideas? How to diagnose further?

Thank you!

Message was edited by: danimir

I've solved this issue - my WD HDD is working again on FW800!!!

The result was a combined approach applying suggestions from several other forums... This is what I did:

1. shutdown your iMac
2. UNPLUG the power mains (important) from your iMac
3. disconnect the hard drive from firewire (and unplug the power supply)
4. leave the computer off the mains for 10-15 minutes
5. plug the power mains back (the hard drive should still be disconnected)
6. boot the computer
7. plug in the power to your WD hard drive
8. plug in the firewire 800 cable (pay close attention to the plug orientation)

the drive mounts up in couple of seconds 🙂

the problem is, as I find out, that I've had a power surge on FW port (there could be several reasons for this - e.g. if you don't pay attention when unplugging your FW cable or hard drive -- shorting some pins in the process, or if there is a power surge on the grid and you're without an UPS, etc...) - which caused the (self-resetting) fuses in my iMac disconnected the FW port!

In order to help the fuses reset you need to power down your iMac and disconnect it from the mains (completely cutting the motherboard off any power)... wait some time for fuses to reset (I suppose "cool down") - and then plug everything back in!

I've lost the whole day on this - hopefully someone else will pick up on this and save some time :))

Cheers! 🙂

Thanks, Danimir, for the follow-up. I have also had some unexpected luck over the weekend. This heatwave drove me to temporarily relocate my 24" iMac to the bedroom so my wife and I could rent a movie from iTunes and enjoy it in bed with the AC.
In that process of diconnecting everything, shutting down, unplugging (twice) I noticed at some point Sunday afternoon, when the computer was back in my office, that my WD drive was working again, showing up in the Finder. I activated Time Machine, it started a back-up almost immediately, and all is right with the world again.
The one thing that seems different from your solution is that I never powered down the WD drive, just pulled the FW800 out of its port on the iMac. It seems the power disconnect from the WD may not be essential, while the power main disconnect to the CPU may have been the ticket..
Thanks again.

I can vouch for Danimir's recommendation. It worked for me & after I download some updates, I'll have to execute again! May be an inherent problem if you want to use the external hard drive between 2 different computers. And I've found out the hard way that you can't have both computers connected at the same time, even though you've got the available connections on the hard drive. (simple me, I thought I could use the FW800 port on my iMac and the FW400 port for my MacBook... crashed my external hard drive, was able to resurrect by reformatting, luckily, only TimeMachine backups)

Now a question for the group --- is the firmware update available from WD for Leopard recommended to install? http://support.wdc.com/product/download.asp?groupid=113&sid=60&lang=en I saw this on WD's website. Any feedback? Of course, it indicates to only install via a FW connection.

I have the same problem with a WD my Book pro II

When I connect through FW 400 everything is fine but through FW 800 the external disk will not mount and DiskUtility shows a Windows formatted drive although the drive has a GUID partition.

Well thanks everyone for steering me clear of the iMac 400 Firewire port.

I just bought a WD MyBook at Costco... 500 GB.

I'm having ALL the exact same problems you all reported... but I can tell that it's not going to be worth the hassle to me to go through the complex restarting & mounting process every time I need to start up the WD.

I'll guess I'll just stick with the slow old USB, which works fine... and leave the Firewire to some other system that actually works!

I've noticed Firewire connections can be the devil sometimes compared to USB. So much for progress, I guess...

Time for that new USB port extension hub.

But a big THANK YOU to all the smart people who figured this all out for us... and it wasn't the tech crew at WD or Apple.

:0)

I think you have a bad drive. I have the 1TB My Book Quad interface (USB 2.0, FW400, FW800, and eSATA) connected to the FW800 port on my 24" iMac and it works great as a Time Machine drive. If there is any way you could try this drive on a different Mac to confirm it you should do so.

This worked for me as well. I have a Western Digital Studio Edition. I wouldn't mount unless I attached the cables in that order. I didn't need to download any firmware upgrades.

I've tried most everything recommended here, but to no avail.

He's the error message I get when I try to run First Aid on my WD Terabyte:

http://img401.imageshack.us/my.php?image=snapshot20081002075002zj6.png

I can't partition or restore the external because I already have roughly 400gb of information on the disk. Partitioning or restoring the drive would wipe that info away.

The hard-drive on my MacBook crashed and I just threw in a new one today. I desperately need to access the TB because it has all of my info backed up on it.

Suggestions??

I've tried most everything recommended here, but to no avail.

He's the error message I get when I try to run First Aid on my WD Terabyte:

http://img401.imageshack.us/my.php?image=snapshot20081002075002zj6.png

I can't partition or restore the external because I already have roughly 400gb of information on the disk. Partitioning or restoring the drive would wipe that info away.

The hard-drive on my MacBook crashed and I just threw in a new one today. I desperately need to access the TB because it has all of my info backed up on it.

Suggestions??

Fantastic, danimir. It took more than "a couple of seconds" for the WD to kick in but I did not despair. :))

I also had problems with a WD MyBook 1TB and an iMac Alu 2,4.
I've tried everything without success.
Finally, my WD drive mounted again on the desktop when I also chain connected a very old "Oxford" 60 GB drive on the same FW 400 port.
Could this strange behavior explain the nature of the problem ?

Thanks for your answers