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Thread: Vast box issue

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    Default Vast box issue

    Hi everyone.

    I am in need of some help.
    My family bought a home that is sat TV only and the old owner has left a r##ted box.
    It first had issues and I hot swapped it with a known good box from my rental I moved out from and bingo, tv works.
    After a day of trying everything it doesnt even power up.

    A quick gander on this forum and I go in search of bulging and split caps. 2 found and replaced. We are alive again.

    The box works, but wont display through HDMI except for the home screen for like 2 seconds upon startup.
    If I connect up a set of rca I get audio, no video.
    Whilst I was sitting there in dismay the audio came through the hdmi but then was gone again.

    any pointers before I throw it across the room? I sort of am in need of abc kids.......



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    Default

    Make and model of decoder?

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    Default

    vast dsd 4121

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    If you don't have an ESR meter to check the other electro caps, I would be replacing them as well, even if they don't show any physical signs of failure.

    There are also two 1M Ohm resistors R3 & R4 which are prone to going open circuit.

    Replace both, even if only one is open.

    Be careful, as they act as bleed resistors and mains supply C1 remains charged for a long time, so you need to ensure it's discharged before working on the power supply.

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    cheers.

    r3 and r4 are not testing as open circuit.

    I just popped out the other board and it looks like radiated white/ water marks, presumably the acidic flux working its magic over a decade.
    A few poor solder joints I gave a birthday, will see in 10 mins....
    Last edited by gangus; 25-01-18 at 11:57 PM.

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    Default

    Tnx MTV. I have just repaired another dead 4121. C10 had popped. Cost was $1.15 @ Jaycar

    Cheers
    Hos Here

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    Quote Originally Posted by hos here View Post
    Tnx MTV. I have just repaired another dead 4121. C10 had popped. Cost was $1.15 @ Jaycar
    There's a good chance other caps will follow.

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