What is the original Power Adapter for Western Digital UBS2 External Hard Disk Drive WD1200B008-RNN? Is DC12V 1.5A or DC12V 2.0A. Thanks.

You can't replace it, there are no replacement parts for it. If something failed you replace the entire case. So just get a new one from here
http://www.newegg.com/Store/SubCategory.aspx?SubCategory=92&name=External-Enclosures
Just match the size and type of your hard disk - in your case an 3,5" and SATA.

You can use it, just make sure that the polarities are the same as the original.

This hard disk is dead. You may be able to purchase another hard disk and insert it into the Western Digital USB adapter case.

Any external disk-drive as small as 80GB is probably "out-of-warranty" -- it's likely that the disk-drive inside the enclosure has "died".

You have two options, not mutually exclusive:
* exercise the Western Digital "Customer Loyalty" program -- find the serial-number of your Passport, and access WD's web-site to buy a new Passport, citing the old serial-number to qualify for a significant discount on your purchase;
* open the enclosure, disconnect the disk-drive from the USB-to-disk-drive adapter, buy a new, compatible, disk-drive, and connect it to the USB-to-disk-drive adapter, to "frankenstein" it, creating a "new" external storage-device.

If the hard disk is not spinning then the hard disk is faulty.
The adapter case may be OK especially when you plug it into a working computer's USB port and it detects the adapter but not the hard drive.

first of all , you are looking at the wrong voltages. The important voltage is the DC OUTPUT, which is the voltage the external harddrives use AND the polarity of the plug attached to the harddrive end of the cable.
if both the harddrives have say 12v dc output and both have the insignia of the center conductor being + (posative) then you can interchange them. and you CAN run a 9volt unit with 12volt DC power, but not the other way around.
Look at your power adaptors again for the OUTPUT and polarity.
should be a half-circle with lines depicting the polarity(+,-) of the center and sheild connections to the hard drives printed on both the harddrives and the power adaptors . This can also be tested with a dc volt meter while the adaptors are plugged into the wall.
DO NOT try to test the AC end while plugged in!!
Regards

You've tried different USB cables; so, that cannot be the problem.

You've tried connecting to different computers; so, the problem is _not_ your computer.

What's left is "inside" the case:
* the USB-to-disk-drive adapter,
* the disk-drive.

Open the case, and remove the disk-drive, and connect it as a "slave" drive to some computer.
If it is detected, then the USB-to-disk-drive adapter that has failed.
If it not detected, then the disk-drive itself has failed.

FInd the serial-number on the Western Digital disk-drive, and enter it onto Western Digital's web-site, on the "check-warranty" page. If it's older than 3 years, the warranty probably has expired, unless you were "lucky" and got a 5-year warranty.

Western Digital has a "Customer Loyalty" program -- just buy a new Passport through their web-site, and cite the serial-number, and you'll get a significant discount on _their_ price (could be higher than your local retail computer-store) for a new (probably larger) Passport.

I had a similar problem with some other brand of external drive. I disconnected it without being stopped and then nothing would recognize it. It was new when this happened, I contacted the manufacturer and they sent me a files with software and instructions to recover it. It was not that easy since I'm no computer geek, it took quite a while but finally the drive worked again. Info was lost since I had to formated it, can't remember exactly is low level formatting but alive again.
Also try to go to my computer icon on the desktop and right click, go to "manage" there you'll see an option for disk management, there you might be lucky and make it work again.
Hope this helps, regards.

This is mostly a power issue, although higher speed devices also tend to need shorter cables due to latency. Light & electricity travels about 1 foot, or 30 cm, in a billionth of a second; this limits the size of high speed devices. In layman's terms, latency is the Brontosaurus effect, since the head takes a while to talk to the tail.

Western Digital recommends using a 22" USB 2.0 Power Booster Cable (WDCA029RNN) to combine the power of two USB ports into the one Passport Essential USB port--it is also a bit longer than the original 18 inch cable. For all EXCEPT the black Passport Essential drive, you may also the WD Passport™ Power Supply Adapter (WDPS021 for the US voltage version). See Western Digital knowledge base ID 1296 for more on this issue. Also see ID 1048 for European Support info.

Hope this helps!