Connect with us

Amstrad NC200

Discussion in 'Electronic Repair' started by Nick, Sep 8, 2005.

Scroll to continue with content
  1. Nick

    Nick Guest

    Hi all

    I have an NC200 which works fine except the floppy disk drive which
    appears to be unserviceable.

    I have stripped the drive and a little hair spring about an inch long
    fell out but I can't see where on the drive internals it was supposed to go!

    When a disk is loaded and I try to access the drive the stepper motor
    drives the heads towards to end of the motor thread and then end stops.

    What I really need is a scrap NC200 with a 'known good' drive.

    Can anyone help please?

    Nick
     
  2. Dave D

    Dave D Guest

    I'm not familiar with this model, I assume it has a standard 3.5" floppy,
    and not an old 5.25"?

    If the drive loads/ejects discs properly, and the heads snap shut against
    the disc when inserted, my guess is the spring doesn't go anywhere! 9 times
    out of ten, when I extract springs from floppy disc drives, the spring
    jumped out of a faulty floppy disc and into the drive mechanism. The spring
    is usually the one which closes the protective metal slider on the disc
    itself.

    If I'm right, this could mean that a faulty floppy disc probably fell apart
    inside the drive and was forcibly extracted, damaging/misaligning the
    drive's read/write heads. Is there no way a standard floppy disc drive can
    be fitted? Repairing faulty floppy disc drives is rarely successful.

    Dave
     
  3. Nick

    Nick Guest

    Dave

    I agree re the spring; the one that fell out does look suspiciously like
    those used to close the shutter on a 3.5" floppy disk.

    When I first powered it up I tried to format a 720kB floppy and it went
    all the way through to track 80 but then said there had been an error
    and the disk had not been formatted. I then tried a 1.44MB (didn't
    realise at the time it was a DSDD drive) and had similar results.

    The following day I tried it again with the 720kB floppy but the heads
    moved all the way to the centre of the disk and the stepper motor
    started slipping with a buzzing noise until I popped the disk and the OS
    trapped the interrupt.

    That's when I removed the drive and the spring fell out.

    I cleaned the heads and checked the connectors both external and
    internal to the drive, but no go.

    I then confirmed from the spec that the NC200 has a 3.5" drive which
    formats DSDD DOS compatible i.e. 720kB.

    But the interface looks non-standard. It's only got 26 pins vs. 34 pins
    on a standard PC FDD. It's a Z80 based machine so I will inspect the
    motherboard to see what disk controller it uses. It may then be
    possible to interface a PC FDD to it.

    The easiest solution would be to find a scrap machine and change the drive.

    This machine only cost me 70p so fixing it makes no economic sense, but
    I have this irrational desire to restore it to full working order!

    Nick
     
  4. Asimov

    Asimov Guest

    "Nick" bravely wrote to "All" (08 Sep 05 21:31:19)
    --- on the heady topic of "Amstrad NC200"

    There is a spring that goes on the loading arm of the upper head
    assembly. If it fell out then the heads might not be reading properly.
    If you feel no tension when trying to lift the upper head that is it.
    What did you do to the drive that resulted in the spring falling off?
    Those old 5-1/4" drives bring back memories.

    A*s*i*m*o*v


    Ni> From: Nick <>
    Ni> Xref: core-easynews sci.electronics.repair:341672

    Ni> Hi all

    Ni> I have an NC200 which works fine except the floppy disk drive which
    Ni> appears to be unserviceable.

    Ni> I have stripped the drive and a little hair spring about an inch long
    Ni> fell out but I can't see where on the drive internals it was supposed
    Ni> to go!
    Ni> When a disk is loaded and I try to access the drive the stepper motor
    Ni> drives the heads towards to end of the motor thread and then end
    Ni> stops.
    Ni> What I really need is a scrap NC200 with a 'known good' drive.

    Ni> Can anyone help please?

    Ni> Nick

    .... Back when I was a boy, we carved our own ICs out of wood.
     
  5. Dave D

    Dave D Guest

    A lot of the pins on standard floppy drives are grounds. If you can find the
    data on the floppy drive interface, and cross reference it with a standard
    PC floppy interface, you may find that the Amstrad interface is simply a
    variation minus a few grounds. If it is, it should be fairly
    straightforward to knock a cable together and replace the existing 3.5"
    floppy with a standard one.

    I used to occasionally work on Amstrad gear years ago and I do recall some
    non-standard floppies. ISTR some early Compaq PCs went down that route as
    well. Unfortunately I no longer have any data on the old Amstrad stuff.

    Dave
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-