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@googlegroups.com wrote:

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Just got a possible prototype Widget disk - any special considerations?
Jason Perkins <perkins.jason@gmail.com>: 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@cybermesa.com>
wrote:
 
 
--
Jason Perkins
313 355 0085
PSchaefer <dr.p.schaefer@gmx.de>: 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@gmail.com>: 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@gmail.com>: 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@gmail.com>
wrote:
 
 
--
Jason Perkins
313 355 0085
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