I have a Western Digitial WD800JB. It's a 7200RPM 80GB IDE
drive. It does not spin up. With the disk out of the computer
I hold it vertically and turn the case. I can hear the platters
inside turning. I would like to determine if I am having a
voltage problem.
Measure the voltages at the drive circuit board with a digital meter
-- cheap, simple, and almost obvious. You can also measure the AC
voltages at the motor contacts, and while I don't know what they're
supposed to be, you can compare them to those of a working WD drive in
the same series, as your WD400JB may be. Be careful not to short any
contacts together or to any metal.
When you tested the drive with another power supply, did you plug it
into the 40-pin cable? If so, try it with the cable disconnected
because some drives will spin only without the cable, indicating a
problem not related to the motor.
It's still under warranty. Most of my data has been backed up.
There are some pictures and a few documents I'd like to recover.
I'm guessing that I have to uncover the platters in order to get at
the motor and that will pretty much ruin everything since I don't
have clean room. What are your thoughts on my chances of replacing
the motor? Any recommendations on how to proceed?
With drives about 100M-1G and larger, the moment you remove the cover
you virtually ruin the drive and at least double the cost of data
recovery.
Also WD motors seem to be installed from the inside, meaning any
replacement requires removing the platters and therefore ruining the
alignment of all but the first platter (it has the servo marks written
on it).
Since you can hear the platters turn, the motor bearings have
obviously not seized, so about the only thing lefts in the motor
itself are the windings, one of which may have shorted. But just
because a motor doesn't run doesn't mean it's bad because the real
problem could be in the chip that drives the motor, and in some
installations that chip can exceed 80C, especially if the drive is
horizontal, has less than .5" of space around it, no air blowing over
the circuit board, and the chip faces the drive body.
The only practical repair you can do yourself is a circuit board swap
from another identical WD800JB drive, but don't assume that all
WD800JBs are identical; look at the suffix to the part number to make
sure they are. I have, for example, a WD1200JB-00DUA3 and a
WD1200JB-75CRA0, and they differ in the number of platters and their
circuit board layouts (I have no idea if the boards are
interchangeable).
If you open the drive, you'll lose your drive and your data and make
data recovery cost much more. If you leave the drive closed you'll at
least get a replacement drive.