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Searching part number for 690KE

Discussion in 'Datasheets, Manuals and Component Identification' started by KSB, Dec 17, 2015.

  1. KSB

    KSB

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    Dec 17, 2015
    Hi, Help me to find the actual part number for 690KE component.
     

    Attached Files:

  2. davenn

    davenn Moderator

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    Sep 5, 2009
    hi there
    welcome to EP

    what is written in white on the PCB directly above the part ? ... I cant tell because of all the solder flux
    it will hint at a component type to search for


    Dave
     
  3. KSB

    KSB

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    Dec 17, 2015
    Hi Dave, Thank you for your reply. The white marking on the PCB written as U8
     

    Attached Files:

    • U8.jpg
      U8.jpg
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  4. 73's de Edd

    73's de Edd

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    Aug 21, 2015
    .



    Sir KSB . . . . .


    I also am having definition percepton limitations on the PCB's surrounding foil paths.

    BUT . . . . most common normal component I.D. assignments are using R prefixes for resistors, C for capacitors, Q for transistors, and U for integrated circuits.
    In this case of the U assignmant, the strongest initial consideration would be for a mere 3 terminal unit, to be a "3 terminal regulator".

    Look closely at its interconnects and it seems that the power buss foil comes in at the right top of the device and connects to its central top connector and then
    moves to the left and drops down and then loops over to the right of the device, thereby making a shorted connection.
    Nope . . . . three terminal regulators don't utilize that "silly" manner of connections.

    Considering that the unit might really be a transistor, if the top terminal is being its collector and looping down to short to the base ( left terminal) of the device, that would let a transistor
    be used as a diode. (Producing the same junctions thermal tracking considerations that might compliment a like transistor used with it in adjunct circuitry)
    The far right connection would be its emitter.
    The nearby 4.7 k chip resistor seems to be shunting across the then created diode . . . . from power buss to emitter.
    Aditionally, I wouldnt percieve of the unit as being a Zener diode , due to that shunting resistor.

    What say you . . . .or others ?



    73's de Edd


    .
     
  5. dorke

    dorke

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    Jun 20, 2015
    Can you draw the circuit around the device?
    Does it connect to a μC ?
    a clear and wider photo may help.
     
  6. KSB

    KSB

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    Dec 17, 2015
    Attached the complete PCB with track connection. Its a LCD monitor PCB.
     

    Attached Files:

  7. dorke

    dorke

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    Jun 20, 2015
    O.K
    The 690KE is most probably a power on reset IC.
    It seems to monitor the input voltage(5v?) of the 1086 3.3v regulator.
    The 690KE output is feed to a transistor(which is it?) probably for inversion and then to pin 111 of the GM5621 IC (RESETn).

    Do you need to replace the 690KE ?
    I couldn't find the actual part on the web but a suitable replacement can be found.
    First step is to measure the voltage on pin 3 of the 1086(red line).
    gm5621-reset.jpg
     
    Martaine2005 likes this.
  8. 73's de Edd

    73's de Edd

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    Aug 21, 2015
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    Sir KSB . . . . .

    If this is sampling a 5V VCC line:

    I think that your mystery SMD, KA coded device is going to be a KIA7042 .

    To test, just place the scope in DC coupling mode 1V DC Vert sensitivity,
    place in auto triggering mode, at a slow / high millisec hoz sweep rate and
    probe to your YELLOW lined reset buss.

    Have the equipment in a drained capacitors power state prior to start up and
    keep eagle eye on scope and power up and confirm a short time lag and then
    the presence of it producing a reset logic blip on the screen.

    After the board is plugged into its connector, if you are in cramped quarters for
    scope probe access to the logic reset line, just temporarily solder tack on a
    small length of Kynar wire wrap to wrap its other end around / clip with your
    scope probe, to get you out of the cramped area.
    (We're not dealing with 500 Mhz RF here . . . you know.)

    Thasssit . . . . . .



    73's de Edd


    .
     
  9. dorke

    dorke

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    Jun 20, 2015
    Well,
    We are getting close, but no cigar yet ;)

    I think your device is G690H438Tx from GMT(a Taiwanese company).
    (Look at page 5 on the datasheet)

    The marking isn't exact(they may have changed it to the more logical 690 from 688.... )
    ,the best would be to contact them and inquire here

    here is a G690 family part with the 690BZ marking on it .
     
    Last edited: Jan 9, 2016
    davenn likes this.
  10. davenn

    davenn Moderator

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    Sep 5, 2009
    Its 690KE not 690KA
     
  11. davenn

    davenn Moderator

    13,164
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    Sep 5, 2009
    nice find

    the difference in KE to BZ etc may be just cuz of being a different manufacturer :)
     
  12. dorke

    dorke

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    Jun 20, 2015
    It is the same manufacture.
    G690/691 is a family of reset parts with different "logic" and a variety of "trip levels" and slightly different packages.(see the table below).
    The "K "-suffix part makes perfect sense to the circuit of the op.

    The strange thing is what went through GMT minds to mark them 688/689 instead of 690/691?o_O...too much rice-booze maybe;)
    So when the booze effect was over they re-marked them the logical way?
    That is why the op needs to contact them,for the final piece of the puzzle.

    G690.jpg
     
    davenn likes this.
  13. KSB

    KSB

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    Dec 17, 2015
    Thank you Dorke, Davenn and 73's de Edd for all your comments. I appreciate very much your suggestions. :)
     
  14. 73's de Edd

    73's de Edd

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    Aug 21, 2015
    Did you ever confirm . . . . . you realy-realy-really should have given us the brand and model of the monitor that it was in.
    I see some of that gm5621 series of u/p's being used in Dell's.



    Matter of fact, some AOC monitors also use that u/p unit for its brains . . . . .but by the time lag passed . . .we might assume that you were just grasping for straws with that unknown . . .to you . .part.

    Here is a typical utilization in this schema snippett . . . .showing all that one would really need to know.

    F.I.O. . . . . . .

    [​IMG]


    73's de Edd
     
    Last edited: Apr 8, 2016
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