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Recapping a DC-DC converter, 12V to ATX, which caps to use?

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    Recapping a DC-DC converter, 12V to ATX, which caps to use?

    This "beautiful" converter board is from an old Mini-ITX case. It uses 12V DC as input and converts it to ATX voltages.
    I'd like to recap it. The machine is in use 24/7 as a router.


    A: "E.V.A. Top" 470µ/16V
    B: Sanyo WX 470µ/16V (in the 12V rail)
    C: (currently four bulged junk caps that need to go) originally these were four green sleeved low quality 1000µ/6,3V caps that blew up years ago (the upper two are in the 5V, the lower two in the 3,3V rail)

    My plan is:
    A: measure, if not ok replace with Chemi-Con LXZ or Panasonic FC
    B: keep
    C: replace with Panasonic FR 1200µ/6,3V, 8x15mm, 1240 ripple, 0.041 Ohms

    I'm not sure about C. Regarding low ESR electrolytics the Panasonic FR series is the best I can get my hands on easily. Could FRs work out?



    Some more pictures ...

    left side of PCB, the markings on the - probably - Mosfet controller chip are scratched off unfortunately



    right side of PCB



    "E.V.A. Top" in all it's glory
    Attached Files
    Last edited by Exim; 11-10-2020, 08:53 AM.

    #2
    Re: Recapping a DC-DC converter, 12V to ATX, which caps to use?

    He put a single - from the color I'd guess MBZ - Rubycon on each rail. So I guess two FRs in parallel on each rail will do the job.
    Last edited by Exim; 11-10-2020, 12:47 PM.

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      #3
      Re: Recapping a DC-DC converter, 12V to ATX, which caps to use?

      Your guess about MBZ is correct
      "The one who says it cannot be done should never interrupt the one who is doing it."

      Comment


        #4
        Re: Recapping a DC-DC converter, 12V to ATX, which caps to use?

        Morex Procase... now that's a name I haven't seen in a while.

        I do have an old Morex ATX PSU from 1998 that I got for free on Craigslist over a decade ago. Recapped it and it's been a super-solid 5V PSU. It's well built (aside from crap caps), so I think Morex made decent stuff overall.

        Anyways, I think the FRs will do fine too. Four of them vs. two MBZ... I think the FRs might win the specs game.
        And maybe replace that EVA Top cap too anyways - at least if you intend to use this back again in 24/7 operation. One extra cap shouldn't break the bank.
        Last edited by momaka; 11-14-2020, 10:21 PM.

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          #5
          Re: Recapping a DC-DC converter, 12V to ATX, which caps to use?

          The four new FRs are in place, board is working fine.
          Didn't bother to take out the remaining general purpose "EVA Top" ones. They all measured "something". Good enough.

          Attached Files

          Comment


            #6
            Re: Recapping a DC-DC converter, 12V to ATX, which caps to use?

            Nice work!

            Originally posted by Exim View Post
            Good enough.
            Ah, that's the perfect enemy of the perfect.
            I'm guilty of doing many repairs like that on my own personal stuff, too.

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