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Clevo M670SRU Part 2

Discussion in 'Notebooks' started by nick, Feb 10, 2010.

  1. nick

    nick Flightless Bird

    Some of you may recall my earlier post about the charging (or lack of)
    on this laptop. Here's an update, and a question.

    I don't have the original adapter (19v 4.74A), so I'm running the
    laptop off a beefy HP 19v 7.1A adapter.

    1. With no battery fitted the laptop won't run off the adapter.
    Press the power switch and the power light blinks once and that's all.

    2. With a charged battery fitted and no adapter the laptop will switch
    on and runs normally until the battery goes flat.

    3. With a charged battery fitted and the adapter plugged in the laptop
    will switch on and runs normally for as long as you like. The battery
    does not discharge from day to day.

    Tests with an Avo confirm that the laptop is running off the adapter,
    and is drawing about 3A.

    4. Unfortunately the laptop never charges the battery; the charge light
    never comes on. I'm using an external charger to top up the battery at
    the moment.

    Anecdotally the laptop should switch on and run from the adapter
    alone, thus indicating that there is a fault in the laptop.

    But before I rip it apart I've heard rumours that running a laptop off
    the "wrong" adapter can cause strange behaviour.

    I think that if an adapter is the right voltage and is capable of
    supplying the maximum current required by the laptop and battery then it
    should work just as well as the original.

    Does anyone here know different?
     
  2. Barry Watzman

    Barry Watzman Flightless Bird

    The part of your post I left below is generally correct for AC adapters
    that connect to the laptop with only a 2-wire connection (usually a
    coaxial barrel connector). However, if the laptop has additional wires
    in it's connection, then it's completely proprietary as to how it and
    the laptop work (some of the power supply circuitry is in the AC
    adapter) and no generalizations can be made.

    Also, Dell and perhaps others have managed to incorporate some type of
    "communication" between the laptop and the power supply (even when the
    power supply is only a 2-wire supply) and the laptop won't fully work
    properly with a non-OEM (Dell) adapter.

    nick wrote:
    >
    > I think that if an adapter is the right voltage and is capable of
    > supplying the maximum current required by the laptop and battery then it
    > should work just as well as the original.
    >
    > Does anyone here know different?
    >
    >
     
  3. ~misfit~

    ~misfit~ Flightless Bird

    Somewhere on teh intarwebs Barry Watzman wrote:
    > The part of your post I left below is generally correct for AC
    > adapters that connect to the laptop with only a 2-wire connection
    > (usually a coaxial barrel connector). However, if the laptop has
    > additional wires in it's connection, then it's completely proprietary
    > as to how it and the laptop work (some of the power supply circuitry
    > is in the AC adapter) and no generalizations can be made.
    >
    > Also, Dell and perhaps others have managed to incorporate some type of
    > "communication" between the laptop and the power supply (even when the
    > power supply is only a 2-wire supply) and the laptop won't fully work
    > properly with a non-OEM (Dell) adapter.


    Yup, and I think there is a good chance that this is the problem.... As long
    as the battery is fitted the laptop thinks that it's got a source of power
    so boots, then actually draws power from the non-original PSU... Perhaps.
    <shrug>
    --
    Shaun.

    "Give a man a fire and he's warm for the day. But set fire to him and he's
    warm for the rest of his life." Terry Pratchet, 'Jingo'.
    Nota bene: 'Return to' email is very rarely checked, if at all. It's spam
    city but is a req. of my NNTP providor.

    > nick wrote:
    >>
    >> I think that if an adapter is the right voltage and is capable of
    >> supplying the maximum current required by the laptop and battery
    >> then it should work just as well as the original.
    >>
    >> Does anyone here know different?
     
  4. nick

    nick Flightless Bird

    ~misfit~ wrote:

    > Somewhere on teh intarwebs Barry Watzman wrote:
    >> The part of your post I left below is generally correct for AC
    >> adapters that connect to the laptop with only a 2-wire connection
    >> (usually a coaxial barrel connector). However, if the laptop has
    >> additional wires in it's connection, then it's completely proprietary
    >> as to how it and the laptop work (some of the power supply circuitry
    >> is in the AC adapter) and no generalizations can be made.
    >>
    >> Also, Dell and perhaps others have managed to incorporate some type of
    >> "communication" between the laptop and the power supply (even when the
    >> power supply is only a 2-wire supply) and the laptop won't fully work
    >> properly with a non-OEM (Dell) adapter.

    >
    > Yup, and I think there is a good chance that this is the problem.... As long
    > as the battery is fitted the laptop thinks that it's got a source of power
    > so boots, then actually draws power from the non-original PSU... Perhaps.
    > <shrug>


    Thanks guys. I've asked a friend who has the same model to
    check his adapter connector for any sign of a 3rd wire.

    I believe Dell use a 3rd wire. See

    http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed

    Barry, do you know of any specific examples of where communication
    between the adapter and laptop is enabled over only the two wires
    which are carrying the power?

    I'm not saying it's impossible, just unlikely!

    Nick
     
  5. BillW50

    BillW50 Flightless Bird

    In news:hl0vvj$62l$1@news.eternal-september.org,
    nick typed on Thu, 11 Feb 2010 13:16:35 +0000 (UTC):
    > ~misfit~ wrote:
    >
    >> Somewhere on teh intarwebs Barry Watzman wrote:
    >>> The part of your post I left below is generally correct for AC
    >>> adapters that connect to the laptop with only a 2-wire connection
    >>> (usually a coaxial barrel connector). However, if the laptop has
    >>> additional wires in it's connection, then it's completely
    >>> proprietary as to how it and the laptop work (some of the power
    >>> supply circuitry is in the AC adapter) and no generalizations can
    >>> be made.
    >>>
    >>> Also, Dell and perhaps others have managed to incorporate some type
    >>> of "communication" between the laptop and the power supply (even
    >>> when the power supply is only a 2-wire supply) and the laptop won't
    >>> fully work properly with a non-OEM (Dell) adapter.

    >>
    >> Yup, and I think there is a good chance that this is the problem....
    >> As long as the battery is fitted the laptop thinks that it's got a
    >> source of power so boots, then actually draws power from the
    >> non-original PSU... Perhaps. <shrug>

    >
    > Thanks guys. I've asked a friend who has the same model to
    > check his adapter connector for any sign of a 3rd wire.
    >
    > I believe Dell use a 3rd wire. See
    >
    > http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed
    >
    > Barry, do you know of any specific examples of where communication
    > between the adapter and laptop is enabled over only the two wires
    > which are carrying the power?
    >
    > I'm not saying it's impossible, just unlikely!
    >
    > Nick


    Hi Nick! I was thinking in another direction than Barry or Shaun was. As
    I was thinking that at best, maybe a fuselink has blown going to the
    battery charger circuit. At worse, a chip or two has failed.

    As for what Barry was saying... well you can modulate small digital
    signals on a power line without problems (even analog ones if you would
    like). So this isn't a problem. As you do have some leeway as for input
    voltage.

    Another way it could happen is that the laptop could survive a very
    quick power outage (even without a battery installed). But easier yet,
    when the laptop is first turned on, you have many milliseconds to have
    the adapter and the laptop to communicate with each other before
    supplying the full load. The user won't notice that a few milliseconds
    of a delay anyway to do this check. And if the laptop didn't hear the
    right secret code in the beginning, could refuse to accept power from
    it.

    --
    Bill
    Gateway M465e ('06 era) - Windows XP SP3
     
  6. nick

    nick Flightless Bird

    BillW50 wrote:

    > Hi Nick! I was thinking in another direction than Barry or Shaun was. As
    > I was thinking that at best, maybe a fuselink has blown going to the
    > battery charger circuit. At worse, a chip or two has failed.
    >


    My friend has got back to me re chargers. He has used a couple of
    different chargers, neither of them original, with no problems. The
    schematics in the service manual show no trace of a 3rd wire, so it
    looks like the charger control chip has failed.

    Thanks for all the helpful input guys.
     

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