duo p801 different resistances

Discussion in 'VuPlus Duo Hardware troubles and Repair support.' started by daphney, Jun 21, 2016.

  1. daphney

    daphney New Member

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    hi 1st i just found this site great news:)
    i have 2 duos with the red light nothing else problem so i been working on both comparing as i go
    on the p801/5v pic that shows resistance i get low resistances ok on both boxes but 5.34mohms on all test points that shown cant get that meter is on 2000m ohms scale & will read 013 when on 20m scale reads 0.L ie need higher scale any ideas whats open circuit or why resistance is so high ive changed chips & caps& are connected ok
    thanks for the great pics
    thnx for help in advance
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    These measurements were made with a Fluke / Voltcraft and / Extech multi meter and the average values.
    However, it is not excluded that the values may be different with a different multi meter.

    Best is to simply compare the values with your two motherboards.
    If they are the same, the probability is very small that the two have the same defect.

    There are a few things that I first do with a red light, and no further activity problem.

    1. Checking the 3.3v, as you can see here,
    Vu+ Duo red led issue, no access to the receiver solution

    2. Check with Cypress I2C (jtag) board or you get a connection with the cpu.
    To use software, Broadband Studio 3
    If so, it is possible to fix using this method.
    If not, then it is most likely the cpu issue, or at least a voltage to it.

    3. feel with a finger if the coils L802 or L814 or others become hot, which mostly means that a circuit asks to much amps,
    Or the coil itself is defective (burned inside), or the dc to dc ic from that circuit has a issue.

    In any case, it is important to know whether the security chip is still working, because without it has the repair of the motherboard not so much sense.