DM500HD, No channels find

Discussion in 'Hardware troubles and Repair support.' started by bibo1, Jul 10, 2016.

  1. bibo1

    bibo1 Member

    Messages:
    62
    Likes Received:
    17
    Trophy Points:
    8
    Gender:
    Male
    Hi Johnny,
    just another case, another box. With This Box everything is fine, exept the search of channals.
    I cheked the voltages at the 1400 with the following result:

    pin11- grd
    pin12-3,3v
    pin13-3,3v
    pin14-3,3v
    pin15-3,3v
    pin16-0
    pin17-2,5v
    pin18-12v
    pin19-20v
    pin20-grd

    if I go to the signalchecker the most signals are there but no one can be loaded.
    Anything you can see what maybe could be damaged?

    Klaus
     
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,523
    Likes Received:
    1,301
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Often it's just the software, using older versions may give a better result.
    Sometimes it could be the lnb u1400, but since you have the 15/20v it's doubtful.
    Sometimes it's just the lnb connector, which happens more often.
    And sometimes it could be a bad connection between the bcm4505 chip to the tu1400_a connector.
    I think, best is to check these connections if they are all well.
    More about this, see the TU1400-TU1400_A pins (tuner) information post.
    The To/From TU1400_A BCM4505 picture.

    However, lately, and because I have enough spare parts I mostly replace the tuner print with this kind of problems and it mostly helps.
    But not always.
    And if I do that, then I saw the pins with a mini grinder and use a male to male connector for mounting the other tuner module.
    Because removing the tuner print does not always go smoothly when you desoldering it.
    The pcb traces to the solder buses are fragile.

    But still, I always test it with a older image file to see if it's a hardware, or software failure.
    From my experiences the newer software may cause a bad tuner signal.
     
    toysoft likes this.