DM7020 RF output problem

    Box type: DM7020


    I have tried several combinations of HDD's and DM7020's but all seem
    to suffer from the same problem:
    The RF output has severe patterning, on saturated colours, only when
    the Hard Disk is connected, without HDD all is perfect.


    Any ideas?


    Regards
    Mark.

    Just one idea. Have you tried setting the RF modulator to an alternate frequency? It may be co-channel interference
    Strangely enough I dont use the RF modulator but did have a slight interference pattern on my TV when using a 21pin scart cable. (This pattern appeared if the dreambox was on and recording a program to the hard drive and I was watching TV.)
    This disappeared when I retuned the RF modulator to UHF channel 21 (not used in my area)
    also set sound subcarrier to 6MHz and not 5.5MHz

    Thanks but it is not co-channel interference.
    Picture and sound are fine until the HDD power cable is plugged in (even with no IDE cable) then patterning starts.


    DM7025 tested fine, no problem, only DM7020.
    Perhaps no-one uses the RF out ?


    Mark.

    hello! today i bought a new small TV! and just for fun i tried this one on the RF modulator, and get the same problem!!


    without hdd all is ok, except some small "spikes" in the pictures some times..



    if i connect the hdd to the power, without HDD, modulator crashes, and then i have to reactivate it in the menu!


    can this problem be fixed??


    br hk2k2

    Meine Dreamboxen:
    DM920 (1xSi21662D Dual DVB-S2X-MS + 1x 21692D Combo S2X-MS/C/T2)
    DM900 (1xSi21662B Dual DVB-S2)
    DM8000 (1xBCM4501 Dual DVB-S2 intern + 1x CU1216 DVB-C + 1xTU1216 DVB-T)
    DM800SE (BCM4505 DVB-S2)
    2x DM500HD (DVB-S2)

    DM800HD (BCM4505 DVB-S2)

    Leichen etc:

    DM5620S
    3x DM7020S
    DM600S

    .....

    Hi all,


    have a 7020 running here (3 months old). No issues with rf modulator when using HDD. Doesn't seem to be a general design bug.


    Regards, Mamba

    __________________________________
    Dreambox 800/7020, 250 GB HDD, 100 Mbit Lan

    Einmal editiert, zuletzt von mamba0815 ()

    next days i will try to change modulator from an 5620, i have found some datasheets from the modulator, maybe a problem with the power supply line?


    i´ll post results..


    br

    Meine Dreamboxen:
    DM920 (1xSi21662D Dual DVB-S2X-MS + 1x 21692D Combo S2X-MS/C/T2)
    DM900 (1xSi21662B Dual DVB-S2)
    DM8000 (1xBCM4501 Dual DVB-S2 intern + 1x CU1216 DVB-C + 1xTU1216 DVB-T)
    DM800SE (BCM4505 DVB-S2)
    2x DM500HD (DVB-S2)

    DM800HD (BCM4505 DVB-S2)

    Leichen etc:

    DM5620S
    3x DM7020S
    DM600S

    .....

    first results:


    the problem is the power supply!


    i´ve changed 2 capacitors from the power supply line of the modulator, now the picture IS MUCH MUCH BETTER than before!


    C3043 and C3045?



    original size 22µF/25V


    i´ve used 3300µF / 6V3



    there are still some small patterns during hdd access, but it´s much better than before!



    and today i will change the modulator also, maybe this is a better one;)


    here some pics :




    BR hk2k2