I need help with another component ID

Discussion in 'General Electronics Chat' started by Gdrumm, Jan 14, 2014.

  1. Gdrumm

    Thread Starter Distinguished Member

    Aug 29, 2008
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    The power board of a Dell 1504FP computer monitor will not power on.
    The Caps look good, but this component had green and brown crud across 2 pins (middle and right side).

    I looked in my 2 books, and believe it's a Motorola part.
    Numbers are:
    NL237
    MTP
    2955V

    Board says 01, then below pins holes, S D G, with a broad line above that.

    Things it might be (they all look alike to me)?
    Schttky Diode
    SCR
    Triac
    Mosfet
    Zener Regulator
    Fast Diode
    Transistor
    N and P Channel Hexfet

    Once identified, how do I test it?
    Center pin is ground (checking continuity)
    It does not mount to a heat sink.

    I have a Digi Key 2011 book, but man I sure don't know how to use it.

    Thanks,
    Gary
     
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,019
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    To me, "S D G, with a broad line above that", means it's a Mosfet.

    S = source
    D = drain
    G = gate
    And the broad line shows where the tab goes.

    But I have been known to be wrong.:)
     
  3. paulktreg

    Distinguished Member

    Jun 2, 2008
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  4. MrSoftware

    Active Member

    Oct 29, 2013
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  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Correct, they are extremely common PFETs, as are the complimentary "3055" NFET to match.

    Old timers may recognise the significance of the "2955" and "3055" numbers. :)
     
    Gdrumm likes this.
  6. Gdrumm

    Thread Starter Distinguished Member

    Aug 29, 2008
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    36
    Thanks all,
    I will study a Youtube video that expalins how to test it.
    Gary
     
  7. Gdrumm

    Thread Starter Distinguished Member

    Aug 29, 2008
    684
    36
    Happy to report I had a Mosfet in a box of salvaged components.
    Soldered it in, put it back together, and it works great.

    Thanks for your help.
    Another lesson worth some money.

    Gary
     
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