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shortpin to turn a motherboard on

Discussion in 'General Electronics Discussion' started by zulu, Sep 9, 2015.

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  1. zulu

    zulu

    16
    0
    Sep 8, 2015
    Hi everybody!
    I have my laptop motherboard in front of me and I'm trying to figure out how to turn it on without Power button and ribbon cable.
    There is a connector called JSW1 (switch) with 8 pins where to put in the ribbon cable. This connector has the following diagram: [​IMG]

    I just want to short the pins on the base of this connector in order to turn my motherboard on. But which pins? Surely the second one and then?
    Someone has told me to solder a small wire to the second pin and connect it to the ground (areas where tightening screws in the motherboard can act like ground). But I just had a small bipolar cable (like those of stereo headphones) and so I've tried with the ground of this cable (excluding the white and red wires), without soldering anything.
    I've connected one end to the nearest screw slot (for the ground pole) and the other one to the second pin (being careful not to touch the first or the third pin). But all I've got is a spark and some burn on the pin. Perhaps, the ground of my audio cable wasn't suitable for this task or perhaps a solder to the pin is needed (it would be a micro-solder and I don't have any solder for this).
    I just don't want to use a solder but find an "on-the-fly" solution to turn the motherboard on. Someone has used a flat screwdriver to shortpin (normally a couple of pins for other laptop models) but I've seen on the internet that those people use the ribbon cable to do that (perhaps to avoid sparks and burn on the pins located on the base of the connector).
    Any idea about this issue?
     
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    9,880
    2,092
    Nov 17, 2011
    Is this a Clevo D470? The service manual for this shows (page 118 of the PDF) that likely PWRS has to be connected to VIN to turn on the computer (in the schmatic this is done by switch VSW1).

    LID_SW is probably a switch that tells the computer when the lid is open or closed so teh power management can put the computer into energy saving mode or vice versa.
     
  3. zulu

    zulu

    16
    0
    Sep 8, 2015
    It's very similar to Clevo D470. It's a Hyundai P57V, a brand that produced laptops with Clevo motherboards (or, better, produced clone Clevo laptops). Actually, the code of my motherboard is 71-M4000-D04. Casually, I found on the internet the manual of D470W/D480W which is based on a motherboard with this code: 71-M4000-D03. Well, I didn't notice any difference. This is the link: http://www.datasheetarchive.com/dl/Datasheets-USER/DSAUPLD00007992.pdf
    I took the image I uploaded from page 112 (audio out and off board connectors), while SW board and hotkey are on page 125. Actually, a quick comparison between D470 and D470W shows that they're identical (page 118 of D470 manual and page 125 of D470W manual are just the same).

    Anyway, I imagined some logic like the one you explained and I saw, as I wrote, someone doing something like that with a flat screwdriver. Evidently, I was badly advised.
    Now, should it work if I short the first 2 pins on the base of the connector with a flat screwdriver or should I expect dangerous sparks or some possible damage to the pins (and worse to the motherboard)?
    Thanks for your suggestions.
     
  4. Old Steve

    Old Steve

    734
    169
    Jul 23, 2015
    It looks like connecting across from PWRS to Vin should do it.
    I found this on page 123. It's normally low, pulled high to activate:-
    PWRS.JPG

    Disclaimer: Of course, I'm assuming that your board is the same one as in the manual.
     
    Last edited: Sep 10, 2015
    zulu likes this.
  5. zulu

    zulu

    16
    0
    Sep 8, 2015
    Thanks for your answer. Now, to turn my motherboard off, do I have to short the same pins or others? Normally, to force the shutdown of a system a long pressure on the power button is needed. Then, I suppose that the short should last a few seconds as well. Am I wrong?
     
  6. Old Steve

    Old Steve

    734
    169
    Jul 23, 2015
    If that's how it worked when it was last running while fully assembled, with the normal power button, then the answer is yes.
     
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