NOVA4 6070 disk booboo

From: Tom Jennings <>
Date: Wed Feb 2 21:10:39 2005

OK, you all get to laugh if this is a spectacular failure, but if
it's a success, I expect flowers.

So the fixed platter is crashed. It turns out the heads were very
dirty, I was an idiot to not to take the heads *out* for cleaning.
I tried cleaning in-place, but it appeared that there was deep
scoring hard-to-see black streaks).

When I got the heads out, the black streaks, on only the
upper-surface heads (both platters) looked like grooving. Instead
it was very hard gunk/oxide.

The heads are ceramic. So I took a clean, new popsicle stick
(wood) soaked in alcohol, and scrubbed the crap off. The heads are
perfect, with zero scoring or scratches under a halogen lamp and
magnifier. Set these aside.

The fixed platter is trashed. With my calibrated eyeball (English
units) I determined that the removable cartridge has the same,
exact platter inside. Seeing how I have three of them, I took the
platter out. This involved drilling out (GAK!) four
extreme-torque screws [100% tape seal, vacuum, etc]. Extracted
spotlessly clean platter.

Removable platter fits perfectly as a fixed platter. Zero play at
the center ring, zero runout after torquing into place.

Heads installed, loosely. There's a head-alignment procedure, but
I'll set the fixed heads statically since that platter needs a
format anyways. The upper heads I will do the alignment.

Haven't spun it up yet. My main concern, besides dirt, is torquing
the heads in their floating mount during cleaning. But the way
the retracted heads lift, causing a HUGE torque on one side of the
head holder seems really awful, and likely swamps and tiny error I

Even if it works, I can't be too proud of fixing a problem I
caused in the first place.
Received on Wed Feb 02 2005 - 21:10:39 GMT

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