Clevo P640HK - anywhere to source replacement motherboard and/or schematics?

Discussion in 'Sager and Clevo' started by moral hazard, Dec 11, 2019.

  1. moral hazard

    moral hazard Notebook Nobel Laureate

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    Hey all,

    Haven't been active on this forum for a while, still a big fan of Clevo notebooks though !

    I have a P640HK that no longer shows any signs of life (with no real reason/cause).

    The power brick still puts out the correct voltage. Pretty sure something has died on the motherboard.

    I've torn down the notebook to eyeball the motherboard and nothing seems obvious in terms of burned components etc.

    Hoping someone knows where I could find a replacement motherboard at a reasonable price?

    Secondly maybe someone has the schematics for this, that way I can probe some voltages and maybe ID whatever component died on the board ?

    Edit: Found the service manual on premas website.

    Thanks !
    MH
     
    Last edited: Dec 11, 2019
  2. Meaker@Sager

    Meaker@Sager Company Representative

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    I would get a multimeter and see if any of the power planes are shorted.
     
  3. moral hazard

    moral hazard Notebook Nobel Laureate

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    Will do, I'm hoping to find something simple like a failed capacitor.

    Will report back after I've had time to perform the measurements this weekend.
     
  4. Meaker@Sager

    Meaker@Sager Company Representative

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    Depending on where you are even a bad vrm can be replaced if it has not scorched the pad.
     
  5. senso

    senso Notebook Deity

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    First rule of electrical/electronic troubleshooting:
    Thou shalt measure voltages!

    Tear down the laptop, remove the mobo from the chassis, leave only the DC-IN connector if its on a pig-tail, connect the charger to the motherboard and start tracing the power supply path from the DC-IN onwards, its easy to follow the big fat traces at least up to the circuitry of the battery charger, if there is zero life signals, it may be just the DC-IN protection MOSFETs that are busted, usually DFN-8 or SOIC-8 chips.

    You can also find the flash memory that holds the BIOS and measure the voltage on pins 4 and 8 to check for presence of the auxiliar 3.3v, if there is no aux 3.3v it wont ever turn on, those aux 3.3v are derived right at the start of the DC-IN circuitry, usually 2/3 1206 resistors, a diode and maybe a zener to clamp it down to 12 or 5v and then there will be some switch mode regulator to make the 3.3v.

    If you kinda know, you dont need schematics, but I understand wanting them if you dont usually repair laptops.
     
  6. moral hazard

    moral hazard Notebook Nobel Laureate

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    So I've been trying to follow the voltage from the DC Jack and found this MOSFET (in red) that has 19V coming in from the top but no voltage leaves from the bottom?

    Am I safe to assume it's blown?

    The other thing I've noticed which seems odd, the power switch has voltage until the button is pressed, then it shows 0V . Could this mean something is grounded after the power switch or is that normal?
     

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    Last edited: Dec 12, 2019
  7. Meaker@Sager

    Meaker@Sager Company Representative

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    Look at the data sheet for the normal operation of that chip.
     
  8. senso

    senso Notebook Deity

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    Why is it chipped in the bottom left corner?

    Might be blown, or might be part of a regulator, given that its near an inductor, and usually the ones that go bad are the ones right after the DC-IN(marked with 820 P03 C1K0C63), the one that you marked is most likely part of the regulator that charges the battery).
     
  9. Meaker@Sager

    Meaker@Sager Company Representative

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    Could have been where the magic smoke escaped.
     
  10. moral hazard

    moral hazard Notebook Nobel Laureate

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    Appreciate the help so far.
    I feel like I am getting closer.

    The ones marked 820 P03 C1K0C63, measure 19V on both sides so they appear fine.

    Unsure why the other one is chipped, still on the top of my list of suspects.

    The other thing I found was a shorted capacitor (circled in the attached pic). I will try replacing this first, because it's easier. If nothing changes I'll try removing the suspect MOSFET.
     

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