Re: Digest for lisalist_at_email.domain.hidden - 4 updates in 1 topic

I have a working prototype widget hd. If you like, I can pull it out and give you the specs on it for comparison.

Cheers,
Adam

Sent from my iPhone

> On Dec 30, 2014, at 2:43 PM, lisalist_at_email.domain.hidden wrote:
>
>
> lisalist_at_email.domain.hidden Google Groups
> Topic digest
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> Just got a possible prototype Widget disk - any special considerations? - 4 Updates
> Just got a possible prototype Widget disk - any special considerations?
> Jason Perkins <perkins.jason_at_email.domain.hidden>: Dec 29 08:39PM -0500
>
> I wasn't sure either, and also don't want to make a permanent change if
> possible :)
>
> I just took a bunch of pictures, they are viewable here:
> https://picasaweb.google.com/113574813556450463594/PrototypeAppleWidgetDrive#
>
> I added captions to point out the differences.
>
> Pictures of my machine's original drive are viewable here:
> http://compu85.homeip.net/stuff/lisa/Drive%20Cage/
>
> I took those shortly after I got the machine, hard to believe I've had it
> 10 years!
>
> Thanks,
>
> -J
>
> On Mon, Dec 29, 2014 at 2:55 PM, Shirl Casner <shirlgato_at_email.domain.hidden>
> wrote:
>
>
> --
> Jason Perkins
> 313 355 0085
> PSchaefer <dr.p.schaefer_at_email.domain.hidden>: Dec 30 10:35AM -0800
>
> Am Montag, 29. Dezember 2014 20:25:00 UTC+1 schrieb compu_85:
>
> > -No apple serial number sticker on the front, instead a 4 digit SN
> > is written in pen (my other 2 widgets have 5 digit SNs on an Apple
> sticker)
>
> ...and sometimes the serial number is stamped onto the chassis.
>
> > -The Read/Write and Servo boards are different part numbers than
> > my other 2 drives
>
> There are two PCB designs with different part numbers, and each comes with
> at least five revisions (marked from A..Z). Also for the controller -- the
> old one is a small four-layer board, the new one a bigger two-layer design.
>
> > -The MotherBoard has green edge connectors vs. the black on
> > my other 2 drives
>
> ...and some have blue connectors. The same applies to the stopmask of the
> bareboard: there are many colors between yellow an green.
>
> > -The heatsink on the Servo board was trimmed
>
> That is unusual and might be an indication that someone repaired the drive
> and needed access to the servo board. Replace it with something bigger if
> you want to operate the drive for a longer time. The servo driver
> transistors do get hot.
>
> > I was going to pop in the controller from one of my other drives and see
> what
> > happens. However, if there is anything "interesting" on the drive I don't
> want to
> > risk damaging / erasing it. Are there any special steps I should take?
>
> Before powering up, shake it carefully and listen for loose parts inside.
> There is a glass scale inside, a part of the servo system. This is glued to
> the chassis frame. The glue ages, and if the drive is bumped, it may come
> loose. If this part gets into the motor, the whole inside of the drive is
> turned into dust. Unfortunately a very common failure mode.
>
> As the next step, rotate the motor flywheel carefully. If it rotates
> without any irregularities, apply power. After some 30 seconds, you should
> hear a clicking noise, followed with a "squeak-squeak". If not, turn it off
> and check and adjust the brake solenoid on the bottom. Put the drive upside
> down, so that the heads do not move the heads while the drive is not
> spinning.
>
> After the initial "squeak-squeak", the controller board performs a self
> test, then a RW test on a spare track, and finally a surface scan. If
> everything passes and the green light stays on, you can use BLU to create
> an image file. Else, swap boards to identify the faulty one.
>
> Do not touch the adjustment screws on the motherboard unless you know what
> to do. Do not bend the motherboard or lift the drive using it as a handle
> -- this may misalign the pots. Do not swap motherboards, this will not work
> without realignment. And never never never open the drive (unless you are
> sure that it is scrap).
>
> If you know what to do: circuit diagrams and alignment instructions are on
> bitsavers.org.
>
>
> Patrick
> Jason Perkins <perkins.jason_at_email.domain.hidden>: Dec 30 02:21PM -0500
>
> Good to know about the motherboard.
>
> Patrick, did you check out the pictures I posted? It looks like the
> mounting stands were never fitted to the servo board. Were they screw / nut
> on early versions?
>
> https://lh5.googleusercontent.com/-V4qbUsfa-UA/VKH8-Z9ysEI/AAAAAAAAF0o/ly3O9bKFnBY/s800/IMG_20141229_200128.jpg
>
> I did carefully shake the drive and didn't hear any rattles. Upon powering
> it up it spins fine, unlocks the head brake, does the initial squeak squeak
> then seems to get stuck doing the same operation over and over. From your
> notes this would be the r-w test on the spares track. At least the bearings
> are all quiet.
>
> I presume this means the drive needs to be low-level formatted?
>
> Thanks,
>
> -J
>
>
> --
> Jason Perkins
> 313 355 0085
> Jason Perkins <perkins.jason_at_email.domain.hidden>: Dec 30 02:34PM -0500
>
> Here's a nice wobble-cam video of the drive attempting to come up:
>
> https://www.youtube.com/watch?v=eFRTS87hTBQ
>
> -J
>
> On Tue, Dec 30, 2014 at 2:21 PM, Jason Perkins <perkins.jason_at_email.domain.hidden>
> wrote:
>
>
> --
> Jason Perkins
> 313 355 0085
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