dreambox 800hd

Discussion in 'DM800HD Hardware troubles and Repair support.' started by tinoco, Oct 18, 2022.

  1. tinoco

    tinoco Member

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    hello guys I have here a dreambox 800hd that when it starts appears on the dream multimedia display it starts to blink and does not leave here the display always blinking sometimes it starts and stays working the tuner is ok when it starts normal the sim card has
    pin 1-0v
    2 2.1v
    3-5v 4-
    5v
    when it doesn't start on sim card
    pin 1 0v
    2 -0.29v
    3-0.06v
    4-1.40v something here is not here if there is any help would appreciate it thank you
     
  2. tinoco

    tinoco Member

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    good I forgot to inform that the box had a swollen condenser under the tuner the 63mf 25v when it cools it works ok when I'm going to restart it soon the display starts to flash and the two LAN lights are on. some help friends
     
  3. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yeah defective caps are often to see when they are swollen, but not always.
    Best is to replace all four big caps or at least the c112/113/114 to start, because these are often bad.
    Also an good test may be, see if the motherboard stay stable without a tuner and playing some video files with the usb port.
     
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  4. tinoco

    tinoco Member

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    I'll see thank you friend
     
  5. tinoco

    tinoco Member

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    hello, touch the capacitors, everything and nothing, the box works fine, but from the moment the processor warms up when you restart the dreambox appears on the dream multimedia display flashing and then it doesn't come out anymore, the internet lights stay on only when you turn it off for a while it starts working again.
    Another thing that I find strange when the bord blocks dreambox 800 the 5v no longer appears it seems to have a blockage but coming from where I have no idea if there is any help I would appreciate it, thank you.
     
  6. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    DM800HD, the problem, won't restart when the box warms up, but works fine when it's started up, is a known problem, especially with the first version pcb boards after they have been used for a while.

    Sometimes solvable, sometimes not, but may be related to the 12vdc psu, the ampere supply may weak, or the 12v is below the 12vdc limit.
    Use a 12vdc psu with preferably a 3 amp supply delivery to rule this out.
    That can also explain why the 5vdc is missing, the dc/dc converter U6/LT1940 hates a 12v voltage that is too low, or weak amps delivery.

    For the 12vdc circuits, and where it all goes you can see on this drawing.
    For the u6/5vdc, see this drawing.

    And else, when it is not related to the psu, then it could be a cap problem on the 12v side, the c292 680uf/25v, maybe it consumes more amps, caused by age, or other issue with it, or a problem with the u6, see this drawing, do not higher the uf value, use a same value or else slightly lower, because else it may consume by starting up more amps.
    It may also (unfortunately) related to the cpu, thinking about outdated solder balls, but because the 5v is in this case is missing when the pcb is warm, then I don't immediately think of the cpu, rather a weak voltage delivery.

    So I think, test it with another psu, make sure the polarization of the plus/minus side is correct. replace the c292 cap.