Dm800SE U1100, 5vdc information

Discussion in 'Schematic drawings, Pcb images etc..' started by Johnny B., Jun 13, 2015.

  1. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Diagram of the U1100 5v system.

    Including most of the datasheets..

    Dm800se-U1100-etc-drawing.jpg

    Some related U1100 repair jobs,

    Issue, box death, only the 12v 1mA power consumption.
    12v to the U1100 is present, but no 5v output.
    No other lower voltages but the Ohm readings from the P1100 pins are fine.
    Solution, replace the U1100 for a new one.
     

    Attached Files:

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  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    For if you are looking for an alternative solution regarding U1100-LTC3850 and other components related to this circuit, I did a test today with a dc to dc converter and with success.

    This board was further fine, but it had a defective U1100-LTC3850 and a few defective Q1100-Q1103-NTGS3130N parts.
    Also, the front oled display failed on this board, never found why.

    My first step, I've removed the U1100, Q1100, Q1101, Q1102, Q1103, D1101 and the coils L1100, L1101.

    dm800se-u1100-removed-parts.jpg

    Nevertheless, I think that I have remover more than needed, basically is the removal of the U1100, Q1100, Q1101 sufficient when you remove the coils L1100, L1101.

    After It was removed I had taken a Dc to Dc converter board and adjust it to the 5v output, the input is (of course) the 12v Dc.

    The wiring were simple, I had taken the 12v from the D1102 +side which is also after the on/off switch.
    Grounds can be taken from everywhere, I have taken is from the C1113 ground side.
    The 5v need to be connected on the coil L1100 or L1101 5v circuit input side.

    Picture says more, so here it shows how I had wired it...
    dm800se-12-5v-wire.jpg

    And here a picture when it's fully working..
    Click on the picture if you like to see it fully.
    Dm800se-U1100-alternative solution.JPG

    Don't use to thin wires, although the amp shows as if it's not much consumes, it is at least one amps.
    In any case, it is an alternative solution for the 5v delivery which is tested, and works when you have only a issue with this 12vDc to 5v Dc U1100 circuit.
    Also, be aware that when it's mounted on this place and this type Dc to Dc converter, the hdd can not be mounted.
     
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