Inside of some of the models of the hard drive assembly, there is a hard
carbon contact that is resting under pressure against the end of the spindle
shaft. I have seen where this contact starts to resonate, and thus cause a
noise that is similar to a bearing noise. This is very rare, but does
happen. All it would take is a slight difference in the pressure of the
spring metal that is holding this carbon contact to the spindle shaft.
Not all drives use this technique. There are a number of ways in the design
to accomplish this contact system. The purpose of this contact is to prevent
static electricity, or any type of electrical transients to form on the
surface of the disk platters. If this happens, the data can be effected.
A more common cause of noise from the hard disk, is bearing defects, or
failure. I have seen a disk drive with noisy bearings work for a number of
years before it failed. I have seen others, only last a few hours. Sometimes
bearings can get noise when there is a very slight offset in the match
between a bearing or more, and the shaft or bushing that they are sitting
in. This offset just has to be a few microns. If the natural resonance of
this offset is matched to the frequency effect of the spinning of the drive,
then it can make some noise. In most cases this type of noise is harmless,
but annoying.
If there is an actual failure of the bearings, and the noise is being caused
by the disk shaft having some wobble, then there may be some noise.With
time, this wobble effect will eventually get worse, because a breakdown of
the bearing or bushing surfaces is occurring. If a bearing goes too far
offset, a seizure in the shaft or bushing can take place. A bearing can
actually have a binding effect at its points of surface contact. This can
lead to one of many types of failure conditions that can occur in a hard
drive.
The noise in a drive can change with the temperature. This has to do with
the expansion and contraction effects of the parts being effected.
Personaly, if I had a noisy drive, I would get it changed...
--
JANA
_____
Has anybody experienced a whining noise similar to a bad fan from a WD
raptor HDD? I have two fans in the front and thought the noise was from one
of them. Computer is a little over a month old, using two raptors. It only
happens on start up when the machine is cold. If I shut down and boot up
again the noise is gone. Doesn't seem to hurt anything but it's annoying.
Rudy
