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Thread: wanted : Vcore mod for A7V8X-X

  1. #1
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    help me doing Vcore mod for A7V8X-X

    @ Mods : Please change the thread name to "help me doing Vcore mod for A7V8X-X", as there is no existing mods and I would appreciate someone with more knowledge reading this - thanks


    Hi,

    I'm in neead of a Vcore mod for A7V8X-X, [...], but unfortunately didn't find any mods.

    I want to reach around 1,95 Vcore ....

    :-(


    (The stupid Overvoltage jumper does for sure nothing as I checked and most users of the "-X" edition say the same.
    Seems like Asus tricked all -X buyers at this point.)


    Thanks
    Last edited by Mad-Marty; 11-27-2003 at 02:34 PM.

  2. #2
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    Can someone help me with the vcore mod please ?

    I found this old threat about the A7V8X,
    http://www.xtremesystems.org/forums/...%2A+voltage%2A
    going to search for that IC ...

    In that thread they say FB (pin 9) should be connected to ground with a resistor. Shouldn't it be Vsense (pin 10) to ground ???
    This is now obsolete - see next post !
    Last edited by Mad-Marty; 11-27-2003 at 02:27 PM.

  3. #3
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    ok, checked the IC, it's an Fairchild 5093MTC on my board ...

    (located directly above the socket)

    http://www.fairchildsemi.com/ds/FA/FAN5093.pdf




    *still hoping for someone to help* :-)
    Last edited by Mad-Marty; 12-06-2003 at 05:53 AM.

  4. #4
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    ok the chip is this one,
    a fairchild 5093MTC - see pic below.

    Can someone who has more knowledge verify my conclusion :

    a) I think that connecting pin 24 to GND somewhere with a resistor will work.

    b) The resistor I want to start with is 30 Kohm - is this sufficient ?

    Also i measured the overvoltage jumper pins. Pin 1 is carrying 0,02 V. The others nothing.

    By connecting the jumper there is really an increase about 0,02 V - not the expected 0,2 V
    Attached Images Attached Images
    Last edited by Mad-Marty; 11-28-2003 at 05:17 AM.

  5. #5
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    The circuit seems to be implemented as advised in the pdf.

    Resistance for VFB is 4,7 Ohm.
    To get a voltage boost of 0,3 V there need to be around 50 Ohm to ground.
    Last edited by Mad-Marty; 12-06-2003 at 05:50 AM.

  6. #6
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    Ok,

    finally done the Vcore mod.
    soldering a 150 Ohm Resistor from pin 24 (VFB) to ground
    will give you 1,95 Vcore instead of 1,8.

    working perfectly now. :-)

    Special thanks to Mr. Icee & Nemesyzz.

  7. #7
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    Well done with the mod, thanks for sharing.

  8. #8
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    err then should need to sold the resistor on 24 and 7?

  9. #9
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    Have you tried replacing the 150 ohm resistor with a 1k trimmer, setting it to 150, then slowly adjusting it each way very slowly and seeing which way takes it closest to "set" voltage? A variable mod is always much nicer than a static mod I think.

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