18 Feb
2013
18 Feb
'13
11:37 a.m.
Pulled it out, reseated the cables, checked the
connections, plugged it int=
o a big enough power supply,
and gave it another go.
Spun up, head load or lock solenoid clicked, waited about 4 seconds (no sou=
nd of seeking), spin down.
Sounds like the problem might be somewhere in the head positioning or voice=
coil/drive.
It's also possible the heads are jammed, say stuck to the end stop.
It's normally fairly easy to identify yhr positioner coil connections to
the HDA. Most likely it's a fleciprint, but with wider traces than those
for the heads. Actually, the OEM manuals for soem CDC drives give the
pinotus of the intenral conencotrs (!).
If you an find these connections, connect a voltmeter across them. Power
up. Do you get a fairly high (several volts at least) DC voltage across
them once the drive has spun up? If so, then it would appear it's trying
to drive the positioner, but the heads are not moving.
If not, then a possible fault is the power amplifier that drives the
positioend coil. This will eiterh be discrete power transsitors or an
audio amplifier IC.
Of coruse the drive may never be tryign to move the eads because it
thinks the platters are not spinning fast enough.
-tony