3 Jan
2004
3 Jan
'04
12:39 p.m.
On Fri, 2 Jan 2004, Nico de Jong wrote:
Has this drive ever worked in this system? If not, you might be missing
some voltage (like -5V) that's not needed by some drives. Have you
actually checked the PSU voltages at the drive with a voltmeter?
From: "Steven N. Hirsch"
<shirsch(a)adelphia.net>
The "H" model is older and uses a square 6-pin Molex connector (same as
all my other 8-inch drives), so I'm sure the voltages are correct. Title says it. Can anyone point me to online
data for this elderly
device?
No, but I have the straps for teh FD1165-FQ, as used in my media conversion
systems.
I am looking at a "naked" drive right now, with the front towards the
right. I can see a number of straps, e.g. the one called US. This one has a
jumper on the righthand part, and is therefore designated below as US 1
Are you sure the voltages are on the correct pins ?
There are some notable differences between the FD1165H and "-FQ" models.
After reading the service manual on Al Kossow's site (thanks to all who
pointed me there), it seems that the motor is supposed to turn on disk
insertion and is not gated by select or head-load signals - at least on
the FQ variant.
That is quite normal on 8" drives. The mains-powered models keep the
motor running all the time.
So, why on earth would (2) functional drives just decide not to spin? In
the interim, I installed a (mis-matched) pair of one-each Qume and Tandon
1/2-ht. drives in the same box. These work fine, indicating that I'm not
dealing with a power-supply or data cabling problem.
A little poking with a voltmeter shows that the motors in the NEC units
are not receiving power. Once again, the head stepper and head-load are
working properly on these units. Another symptom: The NEC units have (2)
status LEDs on the front bezel; ready and active. The ready LED is
supposed to illuminate when power is applied and a diskette is present.
That's often turned on (as is the READY signal on the interface) by
detecting valid index pulses. So if the disk is not turning, the drive
will not become ready
It does not.
Anyone have a suggestion for troubleshooting?
Yes. Trace back from the motor to find how it's controlled (or if you
have a schematic, look there). Find out what signals are needed to turn
the motor on (e.g. a disk-inserted sensor) and find out which are
missing. Find out where the motor switching circuit gets its power from,
and make sure that's present and correct.
-tony