NOVA4 6070 disk booboo

From: Tom Jennings <tomj_at_wps.com>
Date: Wed Feb 2 17:02:29 2005

On Wed, 2 Feb 2005, Jay West wrote:

> Almost always the problem is failure to completely clean the drive; heads,
> airfilter and ducts, all platters (both surfaces)... you've got to
> disassemble the platters, clean and buff them, clean the head armature, ALL
> internal cavities, etc. Ye

Not gonna do that for this machine. Not all machines deserve that
sort of attention; this one doesn't. There's only so many
mountains I can move with a spoon in one lifetime; currently, that
will be the LGP-21.

The NOVA4 got it's airducts cleaned, PS's bench checked, disk
surfaces inspected as far as I could w/o disassembly. I admit I
did not deeply examine the fixed head set (esp. the top-surface,
hardest to see).

Complete disassembly introduces it's own set of problems itself,
but for the full tilt boogie job, necessary.



> s, it could be a pre-existing crash. The above
> would have caught that ;)

Yes, but I'd never get to it, #1, and #2 an in-place cleaning would
have got this one to the 99% point. I didn't do that.

>> Knowing that the platter was trashed, I took off the dust cover,
>> cleaned the platter with a new pad, and felt for large bumps, and
>> ran the READY sequence again. Crashed two more times then I
>> stopped.
> Yeah, I bet it did ;)

I realized it would never work again! This wasn't a subtle crash,
or the >tink< of a skip. I wanted to characterize it (by ear) after
the head and surface debridement.

> job and buff it. Remove the platter. Also break out a dial test indicator and
> measure the runout/flatness (which you have to do when you replace it
> anyways).

No runoff on the outer edge visible to careful scrutiny; certainly
less than .001"

> The key of course if is there is a designated servo platter, or if the drive
> uses a glass reticule with cylinder markings on it and an optical system. I

No servo track, reticule. I will remove the fixed platter's heads,
clean out the cavity and run the removable cartridge only, at
Bruce Ray's suggestion. I'll examine and photo the bad head, see
what state it's in. I'll leave the platter in place for now and
see if I can find part numbers and if the removable platter's
number matches.
Received on Wed Feb 02 2005 - 17:02:29 GMT