When the MOSFETs go!!!

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  • davmax
    Badcaps Veteran
    • Dec 2005
    • 899

    #1

    When the MOSFETs go!!!

    Often the MOSFETs of the motherboard VRM will be damaged by fault caps. It is hard to find good replacements. Here is where a D2PAK replacement can be obtained:
    http://www.mouser.com/search/Product...ualkey51210000

    and here is the data sheet:
    http://www.fairchildsemi.com/ds/FD/FDB7030L.pdf

    Now we need to find a DPAK version. I will start looking but will welcome inputs.
    Gigabyte EP45-DS3L Ultra Reliable (Power saver)
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    Thermaltake Matrix case with 430W Silent Power
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  • kc8adu
    Super Moderator
    • Nov 2003
    • 8832
    • U.S.A!

    #2
    Re: When the MOSFETs go!!!

    i rob them from otherwise scrap boards.

    Comment

    • PeteS in CA
      Badcaps Legend
      • Aug 2005
      • 3578
      • USA, Unsure of Planet

      #3
      Re: When the MOSFETs go!!!

      General guidelines for crossing to near equivalents, preferably:

      * Equal or higher V(br);

      * Equal or higher I(max);

      * Equal or lower R(D-S On);

      * Equal or lower R(theta j-c);

      * Equal or lower Gate capacitance or Gate charge;

      * If the original is called "Logic Level" it must be replaced with a "Logic Level" device.
      PeteS in CA

      Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
      ****************************
      To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
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      Comment

      • davmax
        Badcaps Veteran
        • Dec 2005
        • 899

        #4
        Re: When the MOSFETs go!!!

        Thanks PeteS for the great guidelines.

        The specific device choice I have offered will cover all D2PAK replacement needs. A suffix L device (logic level) will cover all applications and this device is an L product that has low gate charge and low ON resistance R(D-S On), sufficient V(br), high current rating Id and the heat normally generated in these switches is low so that the thermal resistance (theta j-c) is relative unimportant.

        Still have to find a DPAK device.

        Thanks kc8adu a very good solution that can have risk to the devices during removal for the inexperienced.
        Gigabyte EP45-DS3L Ultra Reliable (Power saver)
        Intel E8400 (3000Mhz) Bios temps. 4096Mb 800Mhz DDR2 Corsair XMS2 4-4-4-12
        160Gb WD SATAII Server grade
        Nvidia 8500GT 256Mb
        160Gb WD eSATAII Server grade for backup.
        Samsung 18x DVD writer
        Pioneer 16x DVD writer + 6x Dual layer
        33 way card reader
        Windows XP Pro SP3
        Thermaltake Matrix case with 430W Silent Power
        17" Benq FP737s LCD monitor
        HP Officejet Pro K5300 with refillable tanks

        Comment

        • davmax
          Badcaps Veteran
          • Dec 2005
          • 899

          #5
          Re: When the MOSFETs go!!!

          The information can now be completed.
          D2PAK is 10 mm in width (FDB7030L as above). Being replaced by FDB 8896.
          DPAK is 6.5 mm in width and FDD6680AS will do this job. It can be bought from Fairchild Direct.

          In fact all can be bought from Fairchild Direct.

          For those in foriegn countries like Trodas it might be best for another member to buy for them and post onward.
          Gigabyte EP45-DS3L Ultra Reliable (Power saver)
          Intel E8400 (3000Mhz) Bios temps. 4096Mb 800Mhz DDR2 Corsair XMS2 4-4-4-12
          160Gb WD SATAII Server grade
          Nvidia 8500GT 256Mb
          160Gb WD eSATAII Server grade for backup.
          Samsung 18x DVD writer
          Pioneer 16x DVD writer + 6x Dual layer
          33 way card reader
          Windows XP Pro SP3
          Thermaltake Matrix case with 430W Silent Power
          17" Benq FP737s LCD monitor
          HP Officejet Pro K5300 with refillable tanks

          Comment

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