Kaypro II drive spin constantly - CP/M

This is a discussion on Kaypro II drive spin constantly - CP/M ; I have an old Kaypro II and it was working fine except for a small quirk. Sometimes, for no appearant reason, both drive motors would start and the drives would spin continuously. No disk I/O was possible after this started ...

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Thread: Kaypro II drive spin constantly

  1. Kaypro II drive spin constantly

    I have an old Kaypro II and it was working fine except for a small
    quirk. Sometimes, for no appearant reason, both drive motors would
    start and the drives would spin continuously. No disk I/O was possible
    after this started though the computer was still functioning. To "fix"
    it I simply turned it off for a time and then back on and all was well.

    Now, however, the drives spin constantly when the computer is powered
    up and it is unable to boot. The start message asking for a disk to be
    inserted is there so I think the computer itself is functioning though
    it is of little use without the disk drives.

    I popped the top off and reseated all the chips but to no avail. I'm
    thinking it is a problem with a chip on the motherboard as both drive
    motors are running at the same time.

    Anyone see this before or have any idea what might be the cause? It's
    a neat little computer, I'd hate to have to junk it.

    Ron


  2. Re: Kaypro II drive spin constantly

    Ron Kneusel wrote:

    > I popped the top off and reseated all the chips but to no avail. I'm
    > thinking it is a problem with a chip on the motherboard as both drive
    > motors are running at the same time.


    Did you try to disconnect the cable from floppy drive to the mainboard?
    If they continue to spin maybe one of the drives has a problem.

  3. Re: Kaypro II drive spin constantly

    This is often caused by a drive data (ribbon) cable installed backwards.


    Ron Kneusel wrote:
    > I have an old Kaypro II and it was working fine except for a small
    > quirk. Sometimes, for no appearant reason, both drive motors would
    > start and the drives would spin continuously. No disk I/O was possible
    > after this started though the computer was still functioning. To "fix"
    > it I simply turned it off for a time and then back on and all was well.
    >
    > Now, however, the drives spin constantly when the computer is powered
    > up and it is unable to boot. The start message asking for a disk to be
    > inserted is there so I think the computer itself is functioning though
    > it is of little use without the disk drives.
    >
    > I popped the top off and reseated all the chips but to no avail. I'm
    > thinking it is a problem with a chip on the motherboard as both drive
    > motors are running at the same time.
    >
    > Anyone see this before or have any idea what might be the cause? It's
    > a neat little computer, I'd hate to have to junk it.
    >
    > Ron
    >


  4. Re: Kaypro II drive spin constantly

    Save for he states it would do it after running for a while. The
    cable flips on it own? Not likely.

    Check for flakey cable (bad internal connections) or failing power
    supply ( voltages low).

    Allison


    On Sun, 28 May 2006 23:56:17 GMT, Barry Watzman
    wrote:

    >This is often caused by a drive data (ribbon) cable installed backwards.
    >
    >
    >Ron Kneusel wrote:
    >> I have an old Kaypro II and it was working fine except for a small
    >> quirk. Sometimes, for no appearant reason, both drive motors would
    >> start and the drives would spin continuously. No disk I/O was possible
    >> after this started though the computer was still functioning. To "fix"
    >> it I simply turned it off for a time and then back on and all was well.
    >>
    >> Now, however, the drives spin constantly when the computer is powered
    >> up and it is unable to boot. The start message asking for a disk to be
    >> inserted is there so I think the computer itself is functioning though
    >> it is of little use without the disk drives.
    >>
    >> I popped the top off and reseated all the chips but to no avail. I'm
    >> thinking it is a problem with a chip on the motherboard as both drive
    >> motors are running at the same time.
    >>
    >> Anyone see this before or have any idea what might be the cause? It's
    >> a neat little computer, I'd hate to have to junk it.
    >>
    >> Ron
    >>



  5. Re: Kaypro II drive spin constantly

    Allisonnospam@nouce.bellatlantic.net wrote:
    > Check for flakey cable (bad internal connections) or failing power
    > supply ( voltages low).


    This is can do, I should still have spare cables from old Kaypros I had
    ages ago. Both possibilities make sense. I'll give it a try.

    Thanks!

    Ron


  6. Re: Kaypro II drive spin constantly

    Ok...

    I replaced te floppy cable with old ones and the same thing.. power up
    and immediately both drives start spinning and stay spinning.

    I put a voltmeter on the outputs of the power supply and got:

    +5.00V
    +11.92V
    -11.87V

    Obviously, the +5V is ok and I suspect the other values are as well.
    Anyone have any more thoughts?

    Ron


  7. Re: Kaypro II drive spin constantly

    Do they stop spinning if the cables is unplugged at the board end
    only?

    One possible cause is one of the 7438 line drivers has failed
    on the kaypro board. There are a few others like the software getting
    lost and hanging/endless looping.

    Allison


    On 29 May 2006 14:34:10 -0700, "Ron Kneusel"
    wrote:

    >Ok...
    >
    >I replaced te floppy cable with old ones and the same thing.. power up
    >and immediately both drives start spinning and stay spinning.
    >
    >I put a voltmeter on the outputs of the power supply and got:
    >
    >+5.00V
    >+11.92V
    >-11.87V
    >
    >Obviously, the +5V is ok and I suspect the other values are as well.
    >Anyone have any more thoughts?
    >
    >Ron



  8. Re: Kaypro II drive spin constantly

    I am jumping into the middle of this, but have you checked the drive
    select and drive motor line (which existed on 5.25" floppies)? It
    has been a LONG time but I believe these were active low.

    Some drives were jumpered such that a drive select would turn them on
    instead of motor on; this was always user-definable. I presume you
    have doc on the floppy cable and can locate the right pins.

    On 29 May 2006 14:34:10 -0700, "Ron Kneusel"
    wrote:

    >Ok...
    >
    >I replaced te floppy cable with old ones and the same thing.. power up
    >and immediately both drives start spinning and stay spinning.
    >
    >I put a voltmeter on the outputs of the power supply and got:
    >
    >+5.00V
    >+11.92V
    >-11.87V
    >
    >Obviously, the +5V is ok and I suspect the other values are as well.
    >Anyone have any more thoughts?
    >
    >Ron



  9. Re: Kaypro II drive spin constantly

    In article <1148743112.653036.191660@j55g2000cwa.googlegroups. com> "Ron Kneusel" writes:
    >I have an old Kaypro II and it was working fine except for a small
    >quirk. Sometimes, for no appearant reason, both drive motors would
    >start and the drives would spin continuously. No disk I/O was possible
    >after this started though the computer was still functioning. To "fix"
    >it I simply turned it off for a time and then back on and all was well.
    >
    >Now, however, the drives spin constantly when the computer is powered
    >up and it is unable to boot. The start message asking for a disk to be
    >inserted is there so I think the computer itself is functioning though
    >it is of little use without the disk drives.
    >
    >I popped the top off and reseated all the chips but to no avail. I'm
    >thinking it is a problem with a chip on the motherboard as both drive
    >motors are running at the same time.
    >
    >Anyone see this before or have any idea what might be the cause? It's
    >a neat little computer, I'd hate to have to junk it.
    >
    >Ron


    This kind of rings a bell -- wasn't there a "cold solder joint"
    problem on some the early Kaypros that would manifest itself
    this way? Or am I mis-remembering things (wouldn't be the first
    time with this 45-year-old brain of mine).
    --
    Jeff Wieland

  10. Re: Kaypro II drive spin constantly

    A quick update:

    The machine is working again. What did I do? Nothing, consciously, at
    least. I pulled the cover off, reset the chips, pulled the power
    connector off to measure the output voltages, and pulled the drive
    ribbon cable off to test other cables (which all acted the same way).
    When I put it back together last night to set it aside I turned it on
    and it was working. I left it on for awhile and the spinning drive
    problem did not come back.

    So, something loose or making poor contact, was "fixed" while I was
    monkeying around with the machine.

    I did find a copy of the Kaypro Troubleshooting Guide online which
    stated that if both drives were spinning with both lights on to replace
    the motherboard

    Thanks for the tips and pointers everyone. At least it is working for
    now.

    Ron


  11. Re: Kaypro II drive spin constantly


    Ron Kneusel wrote:
    > A quick update:
    >
    > The machine is working again. What did I do? Nothing, consciously, at
    > least. I pulled the cover off, reset the chips, pulled the power
    > connector off to measure the output voltages, and pulled the drive
    > ribbon cable off to test other cables (which all acted the same way).
    > When I put it back together last night to set it aside I turned it on
    > and it was working. I left it on for awhile and the spinning drive
    > problem did not come back.
    >
    > So, something loose or making poor contact, was "fixed" while I was
    > monkeying around with the machine.
    >


    Perhaps oxidation... reseating the chips and ribbon cable probably took
    care of it.


  12. Re: Kaypro II drive spin constantly

    On 1 Jun 2006 15:10:50 -0700, "Ron Kneusel"
    wrote:

    >A quick update:
    >
    >The machine is working again. What did I do? Nothing, consciously, at
    >least. I pulled the cover off, reset the chips, pulled the power
    >connector off to measure the output voltages, and pulled the drive
    >ribbon cable off to test other cables (which all acted the same way).
    >When I put it back together last night to set it aside I turned it on
    >and it was working. I left it on for awhile and the spinning drive
    >problem did not come back.
    >
    >So, something loose or making poor contact, was "fixed" while I was
    >monkeying around with the machine.
    >
    >I did find a copy of the Kaypro Troubleshooting Guide online which
    >stated that if both drives were spinning with both lights on to replace
    >the motherboard
    >
    >Thanks for the tips and pointers everyone. At least it is working for
    >now.
    >
    >Ron


    I take it you don't know about pink pearl erasers? Back in the day
    when things started going erratic on older equipment, you would take a
    pink eraser and gently rub on all edge connectors to remove any layer
    of oxidation that might be causing bad contacts or higher resistance.

    With an old ADM3 terminal I even tried it on each ttl chip, I would
    remove it, carefully rub each leg, then reseat the chip back on the
    logic board, it kept the terminal running for an extra 2 years until I
    picked up some surplus televidio 925's.


  13. Re: Kaypro II drive spin constantly

    Jeff Wieland wrote:
    > In article <1148743112.653036.191660@j55g2000cwa.googlegroups. com> "Ron Kneusel" writes:
    >
    >>I have an old Kaypro II and it was working fine except for a small
    >>quirk. Sometimes, for no appearant reason, both drive motors would
    >>start and the drives would spin continuously. No disk I/O was possible
    >>after this started though the computer was still functioning. To "fix"
    >>it I simply turned it off for a time and then back on and all was well.
    >>
    >>Now, however, the drives spin constantly when the computer is powered
    >>up and it is unable to boot. The start message asking for a disk to be
    >>inserted is there so I think the computer itself is functioning though
    >>it is of little use without the disk drives.
    >>
    >>I popped the top off and reseated all the chips but to no avail. I'm
    >>thinking it is a problem with a chip on the motherboard as both drive
    >>motors are running at the same time.
    >>
    >>Anyone see this before or have any idea what might be the cause? It's
    >>a neat little computer, I'd hate to have to junk it.
    >>
    >>Ron

    >
    >
    > This kind of rings a bell -- wasn't there a "cold solder joint"
    > problem on some the early Kaypros that would manifest itself
    > this way? Or am I mis-remembering things (wouldn't be the first
    > time with this 45-year-old brain of mine).
    > --
    > Jeff Wieland


    Matter of fact, there was. The Kaypro motherboard is pretty big, after
    all, and expands and contracts with temp. There's a spot on the right
    rear corner -- part of the power supply circuitry -- where the solder
    tends to crack from the stress. I used to have to resolder mine every
    coupla years.

    Jack

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