I have installed a new hard drive into my iBook but the system doesn't see it.

Looks fine. Should work. Since the old one does work, that rules out the connection. I'll ask to see if anyone else has an idea for you.

Do you hear the drive spin up at all in the iBook? If not, then that's why it's not being seen.

I had an identical problem trying to install a WD 320 GB Scorpio Blue (blue label) drive in my old iBook G4 to replace the 120 GB WD Scorpio drive (yellow label) that I had used to replace the original 30 GB Toshiba drive that had failed. I did the same things you did--the Scorpio Blue worked in an enclosure, but would not spin up at all in the iBook.

I returned the first Scorpio Blue and got in a replacement. Same thing--the drive would not spin up in the iBook, but was fine in an enclosure. It seemed to me that the iBook was not delivering enough power to spin up the drive. I spent a lot of time talking to WD tech support on the phone, and they felt the problem was with the iBook, as you might expect. They weren't much help.

This iBook was the original iBook G4 with the 800 GHz processor. Eventually I used an older 250 GB Scorpio (yellow label) drive, and that one worked.

The 320 GB Scorpio Blue that the iBook would not spin up is working just fine in a 12" PowerBook G4.

I also was able to successfully install two 320 GB Scorpio Blue drives in two of the latest iBook G4's (mid 2005). All were bought from Tiger Direct.

Unfortunately, this probably doesn't help you much. I am convinced that my original iBook was not able to deliver enough power to spin up a Scorpio Blue drive, although it was able to spin up the older Scorpio drive and its original Toshiba drive.

According to the specs of both the drive and the iBook, the drive should have worked, but it didn't. It could well be that one or the other or both were a bit out of tolerance with respect to the power needed to spin up the drive, but I had no way to measure either one.

Unfortunately, WD seems to be about the only one manufacturing these drives any more, so what you may be forced to do is to return that drive and get a replacement, and continue to do so until you get a drive that works. After all, the Scorpio Blue did work in the later iBooks, and it may be that the individual drives vary a bit in the amount of power required to spin them up.

Sorry I don't have a better answer for you. I hope you can find a drive that will work for you.

Good luck!

The same thing happened to me--I could feel some vibrations as if the drive were trying to start up, but it never would actually spin up. Even though WD advertises their drives as "whisper quiet", there is an audible whir that you can hear if you put your ear close enough to it. Listen to it in the enclosure and you'll know what to listen for.

It would still be worth returning the drive to WD. Even if you want to sell it, a new drive in an unbroken seal would likely bring more money than one that has been opened and used for a while, and the new owner can register it with WD and deal directly with them if it doesn't work. Be sure to have the serial number available when you call WD, as tech support won't talk to you without it.

One thing that could be going on here is that at least some of the WD Scorpio Blue drives could be at the high end of their power requirement, which is 5V DC±10%. Suppose the drive requires 5V+10%. Suppose the iBook has the same specs (I'm guessing here), but it's at the low end at 5V-10%. If that were the case, the iBook would not be able to deliver enough power, even if both were within specs.

As an aside, I read some reviews on Newegg when my 320 GB drive wouldn't work, and one persistent reviewer got 7-8 drives from WD and finally got one that worked, which likely meant he finally was able to get one that happened to spin up at a slightly lower voltage. Don't know if you would want to go that route, but as long as your original drive will spin up and the WD drive won't, you might well be able to get replacement drives like this other guy did.

Alternatively, you could sell the WD drive or use it in an enclosure, and try a different brand. I see that OWC carries a couple of Hitachi drives, but only in smaller capacities:

http://eshop.macsales.com/Search/Search.cfm?Ne=5000&Ntt=2.5+hard+drive&Ntk=Prima ry&Ns=P_Price|0&N=6885

It may even be worth a call to OWC tech support and see what they think about your experience and see if they have any recommendations for you. They don't always have the lowest prices, but I've never had any problems with returns if something didn't work

Good luck!