18 Jun
2013
18 Jun
'13
5:36 p.m.
On 6/18/2013 2:19 PM, Tony Duell wrote:
The spindle motor rotates easily, but when I apply power, it tries to
turn on, moves just a bit (like the magnetic field is pulling to some
state) and then stops. A bit later, something turns something off
(there is a slight click), and that's all there is.
Unless that motor changes speed, I would think the controller would be
simplistic, and thus the issue is the motor itself. If, though, there
is more to the controller (it seems to have quite a few wires going into
it), then maybe a portion of the controller circuit is bad. Swapping
(not to start a flame fest) would quickly determine one or the other, it
seems.
So, sticktion does not appear to be the issue.
But, it most definitely is not rotating.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
And, in either
case, I can't hear the ST225 spin up. Should it?
AFAIK The ST225 (like most,
if not all ST412-interfaced hard drives)
should spin up as soon as it gets power. There is no interface cable
signal ot control the spindle motor.
Sicne the rest of the machine is working, it's likely that hte power
supply rails are all present and correct, but it can't hurt to put a
voltmeter on the hard drive power connector just to check. The middle 2
pins are gorund, expect +5V on one of the outside ones and +12V on the other.
However, ST225s are notorious for stiction. The heads stick to the
platters nad the thing can't spin up. WIth nothing to lose (the drive
doesn't work anyway), try removing the logic board from the drive and
rotating the spindle motor in the normal direction of rotation (I think
that's counterclockwise, seen from the PCB side of the HDA). Most likely
it will seem to be stuck. If you give it enough force it will move,
hopefully by freeign the heads from the disks, if you are unlucky it'll
rip the heads off, but the drive was dead anyway... If you can get it to
turn, refit the logic board and try to boot the machine. If it works, at
least you know the controller is working.
-tony