External USB hard drive problem

I have an NexStar 3 2.5" external hard drive enclosure and am having
a problem. I have used this enclosure
successfully with a bunch of hard drives, however I am having a
problem with a Western Digital WD1200UE Drive (120 GB). The drive is
spec'ed to draw 940 mA max.
This drive was the primary drive in a laptop that stopped working
due to RAM problems. The drive was split into two partitions.

When I plug the drive into the computer (using two USB ports) the
computer finds the drive(s) okay, with the two partitions showing up
as E and F drives. The problem is that it shows no data on F drive
(which I know there is) and on E drive it only shows a few levels of
folders and files (the number of levels seems to vary each time I plug
the drive in). When I try to copy a file from the drive I get a
message that windows can't find the specified file.

What is going on and how can I fix it ?

 

Big draw for a 2.5" drive. As you are well aware usb ports (which work on 5v) can only provide 0.5a max each. In this case, connecting the WD drive using the additional usb power cable would be mandatory ie power cable first, then usb.

Questions:
1. Presumably, this WD drive has never been used in an external enclosure before.
2. Have you tested this arrangement using another usb port.
3. Are you plugging the external drive into a laptop or desktop usb port (laptop usb port may sometimes fall short of 0.5a)
4. Odd one now have you tried a different data cable ie the one that has a usb connector on one end and a mini usb on the other.
5. Have you tried plugging this into a powered usb hub.

I would take great care with this unit as it could conceivably damage your usb ports. As you are probably aware most 2.5" drives draw 0.5a.

Good Luck

PS: as an alternative route given the large amperage of this drive, I would be tempted to put this drive into a 3.5" external enclosure with a 3.5" to 2.5" adapter / converter (since most 3.5" external enclosures have their own external PS). I have never had need to resort to this method but have read many posts of people doing such to resolve detection issues with no ill effects.