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Thread: uec dsd 4121 rebooting constantly

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    Default uec dsd 4121 rebooting constantly

    Try changing this cap 470u 16v
    worked for me
    cheers


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    Farmsky (25-04-19),hca (15-06-20),OSIRUS (25-04-19),puca (12-05-19),Softek2 (25-04-19),th37sk (26-04-19),Tiny (25-04-19),tristen (25-04-19)



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    Hi,
    I can only say THANK YOU !
    I can confirm that I now have two decoders with this problem (temperature related) swapped out the cap & both came good. Been on test now for several hours @55C and working. I have a stack almost a metre high which might need the update. I was going to do a bit of investigation over the weekend coming but you have saved countless hours of fault finding.
    It's great to see someone else that still has an interest in fixing stuff.
    While we can buy a new 4921 it does NOT have optical out or a display so remote diagnostics for my clients (& friends) is damn near impossible to achieve. With 4121 boxes I can walk clients through getting a box back on the air & connected to the TV. Most are older & forget how to get pictures back after a storm or mains fail. NAS tell me the next model "might" get a display. I wait in hope.
    Thanks once again for your efforts.
    Regards,
    Softek2

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    Nice work cpd

    It looks like you changed the cap without taking the motherboard out is this correct .... ? (would be great if this is the case)
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    Quote Originally Posted by OSIRUS View Post
    Nice work cpd

    It looks like you changed the cap without taking the motherboard out is this correct .... ? (would be great if this is the case)
    It certainly appears that way.

    Many technicians, once the faulty component has been located and identified, simply cut the component's leads from the top of the board, leaving enough of the pigtails intact so that a new component can be soldered to the old leads.

    Personally, in the interest of neatness, I have always preferred to de-solder the component completely (unless it's too difficult and/or time-consuming).

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    Glad to be of help fellas

    I didn't notice a temp related reboot, but did see that it wouldn't reboot with the card out or decoder in standby

    There is another 470 near it and if you compare the lids of the electros, you may notice that the crook one is ever so slightly bowed up. whereas the other is slightly down

    Yes, I cut the old cap off with a scalpel and soldered the new one on the old legs

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    I have also noticed that the crook caps are much smaller (in size) than the previous or next revision boards. Probable just a dud batch of caps

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    Default

    I had the same problem and on inspection found the cap on the power supply had bulged. I replaced it and it works fine with no rebooting.
    [IMG][/IMG]

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    I have had to change that cap in both boxes I have here as well. Mine were failing at boot before they even finished. Along with a couple more caps that looked a little bit puffy, in the last post above image with a blue mark at 7 o'clock and 10 o'clock. 220 uf maybe?

    As some one said they must have had a bad batch, else used the cheapest they could find.

    Now if somebody can tell me what makes them go deaf when its not the F connector joint.
    Last edited by hca; 15-06-20 at 12:39 AM.

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    Well, changing that power supply cap didn't work for long and after a few days the unit started rebooting again so I changed the cap on the motherboard that cpd recommended. All seems to be working fine now. These caps are a constant problem.

    [IMG][/IMG]

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