MFM Miniscribe HDD does not spin, how to repair??

[lucolego]

Hello,
I am trying to get my 20MB Miniscribe 3.5" hard drive running again.
The problem is that it doesn't spin up anymore when I power it up. I
disassembled the drive's PCB, and swapped it with the PCB from a
working drive, and the other HD works with both PCBs, so proving the
problem is with the spindle motor itself.
Looking closer at it, I notice that when I power it up, the platter
spins about 1/4 of a revolution, then stops forever, until I power off
and on again. Rotating it manually doesn't fix it.

What could be the problem? I feel that if I can get the HDD to
correctly spin again, I should be able to access the data. This drive
is vintage, so I'm doing all efforts to rescue it.


Thanks for any information, any hint, or any similar situation
experienced.


Luc

[BlackST]

The problem is elsewhere. Do you still want to DIY or need professional help ?

[lucolego]

I'd like to DIY and do all I can to rescue this drive... By the same occasion, I would learn more.

[fzabkar]

Could we see some pictures?

Did you measure the motor resistances?

Is there a tach sensor?

[BlackST]

I'd like to DIY and do all I can to rescue this drive... By the same occasion, I would learn more.

Good luck then... Take care as they are 'different' from actual .

Last edited by BlackST on December 8th, 2011, 10:57, edited 1 time in total.

[guru]

what's the Miniscribe model number Miniscribe 8425 ?

[Arthur]

what's the Miniscribe model number Miniscribe 8425 ?

Nostalgic mode on:
Oh, a nice old drive with a stepper motor. Those were the times..
(No, not talking about the spindle motor)
Nostalgic mode off

[BlackST]

what's the Miniscribe model number Miniscribe 8425 ?

/nostalgia_mood =ON

Must be one of those nice puppies.... ah the ol'good times... ENTER BFI... play with head skew.... MFM vs. RLL....

/nostalgia_mood=OFF

Anyway, I still have many here (working!) where more or less the "platform" is the same...

[lucolego]

Here is a small video of the motor behaviour. Only the PS and motor connectors are connected. Connecting the rest doesn't change anything.

Uploading it here doesn't work, so I'm putting it on YouTube.
Just search for "rpmcanada1971" "MFM" "Miniscribe"

Thanks for any hints.

[fzabkar]

Just search for "rpmcanada1971" "MFM" "Miniscribe"

Why??? Can't you just link to it?

[lucolego]

O.K. Here is the link to my video.

Sorry, I'm more used to keyboard typing than mouse clicking.

http://www.youtube.com/watch?
feature=player_detailpage&v=0pbRAp0dR3Y

If it doesn't work as is, please paste it into your browser.

Thanks for any hints.
Louis-Luc