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    Help verifying cross reference of Junk Caps < Nichicon/Chemi-Con

    Working on an:
    MSI K7D Master (MS6501)

    This board blew all these caps within a few months of being put in service when it was new back in 2002. I ordered an exact replacement, swapped it out along /w the Enlight PSU for kicks and its replacement has been running fine ever since. This board (the original) has been in my shop closet the whole time. The currently in-service (replacement) board in the server is swelling some VRM caps & starting to develop stability problems. So I'm going to be fixing up this board and using it as a direct on-site hot swap.

    Caps are as follows.
    *See photos for really high res images, lots of good-res zoom capability.

    16v 470uF (LX) - G.LUXON
    Dimensions DxL: 8x11mm
    Impedance*: 0.093 ohms
    Ripple*: 730 mA
    *nearest physical size @ rated uF

    Only shows these sizes at that value in spec sheet.
    8x15mm (1,000hrs 'down-size') & 10x12.5mm (2,000hrs)

    This one should be able to go up to 15mm in height, just like the Chemi-Cons.
    The board manufacturer chose Lelon (RXA) caps to use in place of the following Chemi-Cons in some areas. These (Lelon) caps have vented and are the ones being replaced. They have the "same specs" as the Chemi-Cons.

    6.3v 1000uF (KZE) - Nippon Chemi-Con
    Dimensions DxL: 8x15mm
    Impedance*: 0.053 ohms
    Ripple*: 1030 mA
    *nearest physical size @ rated uF

    Spec sheet shows larger size of: 10x12.5mm
    Stepping down to 820uF yields: 8x15mm

    Any larger diameter and it won't fit between the PCI slots.
    Any taller and the cap would be above the height of the slot and could interfere with on-card components.


    I wanted to just get all Nippon Chemi-Con's, as there are 11 of these on the board in perfect shape that correspond to the el'cheapo Lelon (RXA) caps they used that are all swollen and and/or vented+leaking.

    Looking at the specs for Nichicon - HZ/HN/HM, they show the 8x15mm size. Each series shows a respective impedance of: 0.014/0.020/0.028 Ohms. *Converted from milli-ohms.
    Ripple, respectively: 2210/1700/1490 mA
    That's quite a bit lower than the caps that I'm replacing. Considering the undamaged Chemi-Cons that'll remain behind in the same circuit(s).
    Is this a problem for either the ESR or the Ripple current?
    Why are these sizes at the rated capacitance not on the respective spec sheets, custom made perhaps?

    Lastly...
    Knowing that Rubycon's are a high quality cap.
    I'm assuming the Rubycon 6.3v 2200uF & 16v 1800uF (HMZ) capacitors aren't of a bad series/year and are safe to leave?
    Date Code: T0141/T0143/T0144
    That should be: Early Oct. 2001, Mid to late Oct. 2001, Late Oct. to early Nov. 2001.

    Also, do I need to worry about the remaining sole X-brand cap placed between the 20-pin ATX conn. & the CPU fan header + choke?
    It reads as: TAYEH 16v 100uF (RB).
    *See attached photos for this cap's location & shot of cap brand marking.

    Spec sheet links.
    https://cdn.badcaps-static.com/pdfs/...d40d80e629.pdf
    http://www.paullinebarger.net/DS/Nic...Z%20series.txt
    http://www.paullinebarger.net/DS/Nic...N%20series.txt
    http://www.paullinebarger.net/DS/Nic...M%20series.txt
    https://cdn.badcaps-static.com/pdfs/...ab0783dab7.pdf
    Attached Files
    Last edited by y_not; 05-13-2013, 10:00 PM.
    How to properly apply thermal grease - Y_not's way.

    #2
    Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

    Basically I'm just unsure if I can go with a lower ESR/Impedance rating than what's there. Due to capacitor physical dimension sizing.

    If going lower in ESR is bad... 0.053>0.028-0.014 (47%-73% lower), does anyone have an idea as to a brand/series I could look at that'd be closer to the ESR I need at the given dimensions?

    I'm assuming they have just improved ESR over the past decade+ and it's not really a big deal, but I just want to be sure. Since I'm totally new at this I'm completely deferring to the board's collective expertise.

    Thanks everyone!!
    How to properly apply thermal grease - Y_not's way.

    Comment


      #3
      Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

      I would use Nichicon HD or HE. If you can't find HD or HE or HM is cheaper, HM would also work, though it's a bit too low on ESR.

      HM > HD > HE

      1000uF 10v Nichicon HE is close enough to 1000uF 6.3v KZE to not worry about it.

      I don't think those KZE have a problem, that's not a series with issues.

      The Lelons will have to go, but that's strange all those caps are swollen - I'd suspect the power supply was dying or sending voltage close to the 6.3v rating of the capacitors. I'd replace those with 10v rated capacitors just to be on the safe side, 8mm caps are easy to find for that rating.

      Comment


        #4
        Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

        OK. If I did understand correct, you have TWO (exactly same) boards, one lasting ~10 years, and one you wish to fix...

        What I'll do, is - compare ALL capacitors on both boards, and use approximately the same on ALL places (including visually not damaged capacitors)...

        Differences on CPU-vrm circuit (if any) could say something more...
        You ran this boards on different PSU-s – that should be taken in account too (post both make and models).

        Comment


          #5
          Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

          IIRC you can treat UCC's KY or KZE series, Nichicon's HE series and Rubycon's ZL series as approximate equals. IF their impedance matches what was in the circuit, go with them. In a good design and with good cooling, those should have long lives.

          You can try looking around Fry's in Wilsonville (if it's not too far from you), but I suspect that if they have lytics it'll be GP and/or crap brands. Check what topcat sells or Digi-Key (I'm pretty sure they have KY, KZE and HE).
          PeteS in CA

          Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
          ****************************
          To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
          ****************************

          Comment


            #6
            Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

            As an aside, if Lelon's quality was as good and aggressive as their sales people, they'd define "World Class".
            PeteS in CA

            Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
            ****************************
            To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
            ****************************

            Comment


              #7
              Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

              Originally posted by mariushm View Post
              I would use Nichicon HD or HE. If you can't find HD or HE or HM is cheaper, HM would also work, though it's a bit too low on ESR.
              I checked out the HD & HE spec sheets. Neither one has an 8mm x 15mm cap. Neither in 6.3v, or 10v @ 1000uF. I could go 20mm in height, but that's quite a bit taller than the KZEs that are there next to them. I have had clearance issues in the past with add-on cards and the caps board makers have chosen to place next to the I/O exp. slots. Usually on lesser known boards that I'd see come in. So I don't want to make the same mistake.
              But I honestly don't know how "tall" the offenders really were, never got out the micrometer. LOL

              Originally posted by mariushm View Post
              HM > HD > HE

              1000uF 10v Nichicon HE is close enough to 1000uF 6.3v KZE to not worry about it.
              The HD series is perfect, but wrong dimensions, too fat and too tall.
              HE is the right dimensions @ 6.3v, but that seems quite a bit higher in ESR to me. This series is going in the other extreme, @ 64% higher ESR.
              It's a server, don't know if I could sleep @ night.


              Originally posted by mariushm View Post
              I don't think those KZE have a problem, that's not a series with issues.
              I didn't think they did, but I just wanted to be sure and run it by everyone here. Seeing as I'm not a cap vet.

              Originally posted by mariushm View Post
              The Lelons will have to go, but that's strange all those caps are swollen - I'd suspect the power supply was dying or sending voltage close to the 6.3v rating of the capacitors. I'd replace those with 10v rated capacitors just to be on the safe side, 8mm caps are easy to find for that rating.
              I thought it was quite common for a whole cluster of caps in a particular circuit, all of the same type+brand to go up in smoke like that. Completely independent of the PSU that is. Every where I read says that, even here on the FAQ, the PSU can do it, but is the least of the contributors, if any in most cases.
              So I can learn more on the matter, was there something on that board that tipped you off to the fact that it was the PSU and not just the caps?

              Who knows specifically what the PSU was, I replaced it to be safe. It was most likely an Enlight PSU, as I recall there were proprietary mounting bracket issues and I had to drill holes to use the 120mm bottom mounted fan PSU I replaced it with. The case is an Enlight pedestal server case, so makes sense.

              Rabbit trail.....
              Enlight PSU's of that rough era were always very kind to me, absolute tanks, every one of them. I only ever had one "bad one" that failed an extended 24hr burn-in. But it later went on to be my bench PSU and pass many another burn-in..... so go figure. It's only a 320w PSU and it'll run modern Core-i7 systems, its over amperage rating is through the roof!! Weighs a stinkin' ton too. I did loan one to a friend once and he managed to kill it after a year, but I kept it. I'll repair it one day soon, just because.

              Anyway, I digress.
              Back on the subject at hand.

              So how much lower can you go in ESR, is there a percentage range?
              The HM series, the highest ESR of the ultra low ESR radials I listed that'll fit @ that voltage+uF rating, are only 47% lower in ESR than the ones already there.
              Last edited by y_not; 05-19-2013, 09:49 AM.
              How to properly apply thermal grease - Y_not's way.

              Comment


                #8
                Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                Originally posted by tmiha71 View Post
                OK. If I did understand correct, you have TWO (exactly same) boards, one lasting ~10 years, and one you wish to fix...

                What I'll do, is - compare ALL capacitors on both boards, and use approximately the same on ALL places (including visually not damaged capacitors)...
                I need to go crack the case on the operating server and see what its VRM caps are, as well as the PCI-X 32/64-bit caps are. But I don't have an ESR meter..... yet. So I can't check them if they're a bad brand and not showing any signs of failure.

                Originally posted by tmiha71 View Post
                Differences on CPU-vrm circuit (if any) could say something more...
                You ran this boards on different PSU-s – that should be taken in account too (post both make and models).
                See my photos, in OP, for the hot-swap board I'm fixing. There should be ZERO issues with its VRM caps. Unless they're a surprise bad series/date.

                See above, old model... long gone. New model, I know what it is, but no time to post the cross reference as to who made it. It's made by the same co. that made Enlight's PSUs at the time, just under a different name. I'll have to get the specifics when I go up to check out the in-svc board later.
                How to properly apply thermal grease - Y_not's way.

                Comment


                  #9
                  Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                  I did some digging and found these, being the closest of any to the ESR rating currently on the board & fitting that 8x15mm or less limit.

                  United ChemiCon - KZH series
                  10v@1000uF 8x15mm = 0.048 ohms (9.5% lower ESR)

                  Chemi-con KZH series Spec Sheet

                  Nichicon - HV series
                  10v@1000uF 8x15mm = 0.046 ohms (13% lower ESR)
                  P/N: UHV1A102MPD6

                  Nichicon HV series Spec Sheet


                  However, neither Mouser or DigiKey stock them.
                  They seem to be for MB use, but are a special "small" p/n.
                  Any idea where to look?

                  If the lower ESR Nichicons will cut it, that'd just make me happy as a clam.

                  Let me know.
                  Thx.
                  How to properly apply thermal grease - Y_not's way.

                  Comment


                    #10
                    Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                    Originally posted by y_not View Post
                    ...I'm assuming the Rubycon 6.3v 2200uF & 16v 1800uF (HMZ) capacitors aren't of a bad series/year and are safe to leave?
                    They should be good, but assuming is not a good thing, it' will better to do a full recap. One thing you can do is to leave them for now and if the board does fine after replacing the failed caps proceed to replace the Rubycons too if you think it's worth.
                    Originally posted by y_not View Post
                    ...was there something on that board that tipped you off to the fact that it was the PSU and not just the caps?
                    I think tmiha71 was trying to say that even if cap's brand is not a good one (poor quality) it's important to look at all the possiblilities that may have caused those caps to fail and one of them may be a PSU with bad caps.
                    About the small capacitor near the ATX connector, I don't think you need to replace it, but you are already recaping the board with quality caps so again if you think the board worth it then why not.

                    Suitable replacements at mouser:

                    Panasonic FC series EEU-FC1C471L
                    470uf/16V 8x15mm Impedance .085, Ripple 730mA

                    Panasonic FR Series 667-EEU-FR0J821
                    820uf/6.3V 8x11.5mm Impedance .056, Ripple 950mA

                    Or if you don't want to go under ripple spec you can use this:
                    Nichicon HM Series 647-UHM0J821MPD
                    820uf/6.3V 8x11.5mm ESR .030, Ripple 1140mA

                    Comment


                      #11
                      Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                      Originally posted by SIDMX View Post
                      They should be good, but assuming is not a good thing, it' will better to do a full recap. One thing you can do is to leave them for now and if the board does fine after replacing the failed caps proceed to replace the Rubycons too if you think it's worth.
                      I would say it prudent to simply leave them alone at this point, being as they are Rubycons and show no physical signs of failure at this point.
                      That aside, when I get my ESR meter I'll check them.

                      Originally posted by SIDMX
                      I think tmiha71 was trying to say that even if cap's brand is not a good one (poor quality) it's important to look at all the possiblilities that may have caused those caps to fail and one of them may be a PSU with bad caps.
                      True, sure, I understand that. But I do know that PSU's are typically the least common denominator.

                      Originally posted by SIDMX
                      About the small capacitor near the ATX connector, I don't think you need to replace it, but you are already recaping the board with quality caps so again if you think the board worth it then why not.

                      Suitable replacements at mouser:

                      Panasonic FC series EEU-FC1C471L
                      470uf/16V 8x15mm Impedance .085, Ripple 730mA

                      Panasonic FR Series 667-EEU-FR0J821
                      820uf/6.3V 8x11.5mm Impedance .056, Ripple 950mA

                      Or if you don't want to go under ripple spec you can use this:
                      Nichicon HM Series 647-UHM0J821MPD
                      820uf/6.3V 8x11.5mm ESR .030, Ripple 1140mA
                      I'll probably just leave the little guy, the Tayeh. I can't even find datasheets on them, let alone any sign of the company. Other than the fact they made some caps and they're on some boards. That's about it.
                      Any idea what it does? I'm thinking it possibly smooths the output of the fan header voltage? Just a guess based on what's near it, nothing more.

                      For the 470uF, I presume you are referring to the lone Teapo next to the AGP slot?
                      That Panny should be fine for that. But I imagine there are many other replacement options as well.
                      I was mainly curious if I should just replace it, or leave it. If it performed a critical job, or if it was pretty minor. For that matter, if anyone even knew, or could tell from the photos.

                      Lastly, I just felt it was odd that it too, did not match the dimensions on the spec sheet.


                      Those other 2 you list puzzle me, as the board doesn't have any 820uF/6.3v caps on it.

                      Did you possibly mistake my size reference? Whereby I listed the nearest uF spec that did match the physical dimensions for the Chemi-Cons/Lelons, as the ones on the board do not match the dimensions stated in the spec sheet.
                      I noted that the nearest step down in uF yielded the proper dimensions. So possibly it had that ESR rating as a compromise, since it's obvious they're custom.
                      Just a shot in the dark, who knows, maybe Chemi-Con was just able to make them fit in those dimensions and doesn't have them in their listed specs.
                      Last edited by y_not; 05-19-2013, 11:54 PM.
                      How to properly apply thermal grease - Y_not's way.

                      Comment


                        #12
                        Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                        I have done some further digging and have landed on the following.
                        Do these look OK for my application?

                        To replace the 13 Lelons.
                        Nichicon HM - 1000uF/6.3v/8*15mm/0.028 Ohms/1490mA ripple
                        p/n: UHM0J102MPD

                        To replace the lone Teapo next to the AGP slot.
                        Nichicon HM - 470uF/16v/8*11.5mm/0.030 Ohms/1140mA ripple
                        p/n: UHM1C471MPD


                        The impedance (ESR) of the 470uF is quite a bit lower, more still than the Lelon<Nichicon. Is this a Problem?

                        I went with the highest not lowest impedance (.028 vs. .053) I could find in that can size, staying at or under the 15mm height restriction and at or under the impedance rating of the KZE United-Chemicon caps that'll be staying in that circuit. All ripple ratings are above the originals.
                        Do you think the impedance/ESR is close enough to not be so low as to cause problems?

                        I thought about stepping up to the higher voltage rating recommended here, of 10v. But I decided I should stick with the same voltage as the 11 KZE caps that'll be staying behind in the same circuit.
                        Is this OK?
                        Or will I actually get an ESR rating slightly higher and a little closer to the KZEs if I go with a higher voltage can, running it at less voltage?
                        It's my understanding that the lower the voltage being sent through the cap (below its rated spec), the higher the ESR goes from its (the cap's) original ESR rating at its spec'd voltage. Is that correct?

                        EDIT: Also, I have read here that you're supposed to replace any "bad cap brands" on the board rated at 470uF or higher. Regardless. Except for Fuhjiyuhi-barf, then they all must go, even the little pencil sticks and short chiclet midgets. But the latter is for another day entirely.
                        Last edited by y_not; 05-22-2013, 01:26 PM.
                        How to properly apply thermal grease - Y_not's way.

                        Comment


                          #13
                          Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                          I got to reading some other posts and realized, despite having looked at it before, that 2,000hrs isn't quite good enough. Considering this thing's sitting in a hot server. It's cooled properly, but it's still HOT!

                          The original KZEs are rated @ ~3,000-4,000hrs.
                          (Remember, the whole case size difference since these are obviously custom.)
                          3k if you go by can size alone, 4k if you go by uF alone.
                          So I'm thinking it prudent to aire on the side of caution and search for a cap /w a minimum of 4khrs, due to the heat and all. I'll use a 3k worse case scenario.
                          Sound like a plan?

                          So I used the parametric search @ Mouser, WOW! I love that thing, like Newegg.
                          I had used it this last round, but I was already narrowing it too much.

                          Well, I dug up these, /w a perfect 8x15mm can size.
                          United Chemi-Con
                          KZH @ 6,000hrs / 0.048 Ohms @ 6.3v/1200uF or 10v 1000uF
                          KZM @ 8,000hrs / 0.045 Ohms @ 6.3v/1200uF or 10v 1000uF

                          The 1st one is perfect, it's within 5/1000's of the rated impedance on the original KZEs.

                          However, here's the conundrum. The KZE's were rated @ ≦±25% on the endurance & shelf life test. The latter of the 2 I doubt matters much in application.
                          The KZH/KZM caps I found are rated @ ≦±30% on those same tests.
                          So I would think it prudent to go with the 6.3v /w the slightly higher capacitance @ 1200uF to acct. for aging and mostly heat.
                          Granted, it is then actually higher in capacitance than the originals on the positive side of the tolerance swing, but at least it doesn't go lower on the negative side of the tolerance swing.

                          Thoughts?

                          I'm pretty sure I have got it nailed this time, that is if my assumptions are based on enough facts in practice and practical application.
                          Sorry for all the questions and just talking to myself here, just bumbling around in the dark a bit, trying to figure it out.

                          Also, what to do on the 470uF G.Luxon cap?
                          Mouser doesn't have the Panny FC mentioned by SIDMX. Would one from the KZH/KZM series work, or is the ripple/esr way too far off spec?

                          Any help you could provide on these last few posts would be super!!!!
                          Thanks a bunch!!

                          P/N's
                          EKZH100ELL102MH15D
                          EKZM100ELL102MH15D
                          Last edited by y_not; 05-23-2013, 02:51 PM.
                          How to properly apply thermal grease - Y_not's way.

                          Comment


                            #14
                            Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                            Originally posted by y_not View Post
                            I got to reading some other posts and realized, despite having looked at it before, that 2,000hrs isn't quite good enough.
                            Seems like I have not read those posts you're referring, 2000 hrs is perfectly fine as long as you use quality caps. ie.- Fujitsu/FPCAP/Nichicon RE Series polymers are rated 2000hrs at 105°C yet they are realiable. However I understand that it is better to go for a higher rated cap if possible but remember that for every 10°C drop in temp below the rated temp (105°C in this case) cap's lifetime virtually doubles.
                            Originally posted by y_not View Post
                            Considering this thing's sitting in a hot server. It's cooled properly, but it's still HOT!
                            And this supports the idea of a full recap, 12-year old caps in a HOT SERVER doesn't sound like the best idea to me, even if they are MBZ, don't you think?.
                            Originally posted by y_not View Post
                            Mouser doesn't have the Panny FC mentioned by SIDMX.
                            Mouser have them in stock, not sure why you can't find them, try here.
                            Originally posted by y_not View Post
                            Any help you could provide on these last few posts would be super!!!!
                            Thanks a bunch!!
                            More options:
                            - Nichicon HE 470uf/16V 8x15mm .087Ω - 840mA - 7K hrs
                            - Panasonic FR 1000uf/10v 8x15mm .041Ω - 1240mA - 8K Hrs

                            Comment


                              #15
                              Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                              Originally posted by SIDMX View Post
                              Seems like I have not read those posts you're referring, 2000 hrs is perfectly fine as long as you use quality caps. ie.- Fujitsu/FPCAP/Nichicon RE Series polymers are rated 2000hrs at 105°C yet they are realiable.
                              Yup, that's what I'm using. Nichicon/UCC
                              Scroll up & have a read @ my last 2, or 3 posts after your's from a while ago.

                              Originally posted by SIDMX
                              However I understand that it is better to go for a higher rated cap if possible but remember that for every 10°C drop in temp below the rated temp (105°C in this case) cap's lifetime virtually doubles.And this supports the idea of a full recap, 12-year old caps in a HOT SERVER doesn't sound like the best idea to me, even if they are MBZ, don't you think?.
                              The caps haven't been in use for 10 years.

                              Here's the basic story.
                              - The server, new, was put in service in August 2002.
                              - This board is its original board, it was only in service on this board for 3-6mo... tops before it started failing due to capacitor failure.
                              - At that time, early/mid 2003 I replaced the board with the exact same model, just had LAN on board as I couldn't get this one at the time.
                              - At the same time, early/mid 2003, I replaced the PSU as well.
                              - I kept the old board, the one with all the blown 1000uF caps, with plans to fix & re-sell it for the client, or RMA it, then resell it.
                              - I never did, it has been in the closet for a decade, just sitting in a temperature controlled environment.

                              So as far as age, yes the Rubycons are old, but they have almost no runtime on them.
                              Since I don't have an ESR meter... yet. I may/may not get one by the time I do this board soon. Considering that, do you think it wise to just replace them (Rubycons) anyway? Even the 11 KZE 1000uF caps that are there and still look fine?
                              I'm fixing this one and using it to replace the one that's currently in service.
                              *See pt. 2.

                              Part 2 of the story is as follows. (Mostly for a separate thread, with pics.)
                              - The board I replaced the original with has been in service for the past 10 years, running on the CWT made ASI nSpire brand 550w PSU.
                              - It has been running 24/7/365. So about 80,000-90,000hrs.
                              - It has Chemi-Con KZG caps on the VRM, one is showing signs of failure.
                              - Teapos occupy the 24 some odd 1000uF caps.
                              - That one KZG that's swollen has been like that for 2-3yrs. It was stable until a few months ago. The client knew about it all along and hasn't been able to spend the money on it yet.
                              - The PSU I just pulled apart last weekend. It has Fuhjihuyi whatever caps aaaallll over it. Apparently these were made by CWT for Antec's TruePower series. But this one is much more "overbuilt" than the Antecs. It does have 4 large Capxcon caps on the DC side, where the Antec's had Fuhjihuyi caps there.
                              Since it is made by CWT directly, it makes sense it would be built a bit better. It has only 1 swollen, short little fat cap around 470uf. Not sure what it's for, it's in an odd place all by itself over by the heatsink nearest the DC rail caps. All the other caps show no signs of failure & no heat stress on the board & no chirping or squealing at all.
                              But that doesn't mean much and I bet it's the majority of its problems and source of instability.

                              The current PSU is going to be replaced.


                              Originally posted by SIDMX
                              Mouser have them in stock, not sure why you can't find them, try here.
                              How certainly odd, I searched for that exact p/n as well as did a parametric search for it & nadda!
                              So weird... but there it is. Go figure.


                              The key thing I need to know, if you or others could help me out with it, is this...
                              Originally posted by y_not
                              However, here's the conundrum. The KZE's were rated @ ≦±25% on the endurance & shelf life test. The latter of the 2 I doubt matters much in application.
                              The KZH/KZM caps I found are rated @ ≦±30% on those same tests.
                              So I would think it prudent to go with the 6.3v /w the slightly higher capacitance @ 1200uF to acct. for aging and mostly heat.
                              Granted, it is then actually higher in capacitance than the originals on the positive side of the tolerance swing, but at least it doesn't go lower on the negative side of the tolerance swing.
                              What do I do here?
                              Remember, I'm restricted on can size. So it's either these or the silly ultra low ESR Nichicons. If they won't hurt, then I suppose they're fine. I just don't know enough about circuitry design to determine if an ESR that stinkin' low, much lower than originally used is going to be a problem for the non-VRM caps.
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                                #16
                                Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                                Originally posted by y_not View Post
                                ...here's the conundrum. The KZE's were rated @ ≦±25% on the endurance & shelf life test. ...The KZH/KZM caps I found are rated @ ≦±30% on those same tests.
                                If you are worried about that KZH/KZM's 30% against KZE's 25% then read again the datasheets, the tests are not the same, runtime and parameters are not the same, in fact datasheets show that the 30% change for KZM was after 8000hrs test, 6000 hrs for KZH and only 3000Hrs for the KZE's 25%, not to mention that all tests were conducted at their respective maximum ratings.
                                Originally posted by y_not View Post
                                So I would think it prudent to go with the 6.3v /w the slightly higher capacitance @ 1200uF to acct. for aging and mostly heat.
                                Short answer is: if both have the same specs theoretically they will degrade in the same time, the explanation is quite extensive so i suggest you to google for "capacitor failure modes" to get a better idea because capacitors not only fail when they lose their capacitance.
                                Originally posted by y_not View Post
                                Considering that, do you think it wise to just replace them (Rubycons) anyway?
                                MBZ are pretty good caps but that doesn't mean that they are still good after 12 years without use, they could be good and/or just needing some reforming, however without an ESR meter IMHO the safest/smartest thing to do is to replace them, because deciding by "gut feelings" could put the reliability of your board in jeopardy, but in the end it's your call.

                                Originally posted by y_not View Post
                                What do I do here?
                                Remember, I'm restricted on can size. So it's either these or the silly ultra low ESR Nichicons. If they won't hurt, then I suppose they're fine. I just don't know enough about circuitry design to determine if an ESR that stinkin' low, much lower than originally used is going to be a problem for the non-VRM caps.
                                The only way to tell for sure the circuit's ESR tolerances is to actually know the full circuit's operation (or to have previous experiences recaping that board), since the circuit is unknown then the safest option is to match as close as posible the specs of the original caps, but if you are willing to experiment a little and gain some experience in the process you could try with lower esr caps than original ones and see what you get

                                ... just kidding
                                One thing you should have in mind when experimenting is your skills with the soldering iron as you could damage the board's traces/vias between cap changes so if you don't feel confident in your skills better to not experiment at all, anyway good luck!

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                                  #17
                                  Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                                  Thank you so much Sid, for all of your help and wealth of knowledge.

                                  I'm finally at a point where I can proceed with this, going forward I will have to do without an ESR meter as I'm still waiting on stock from Russia. Soon, it has cleared Russian customs, but it's not here yet.

                                  So for now, the plan going forward is to replace all possible suspect, or old aging caps.

                                  Originally posted by SIDMX
                                  If you are worried about that KZH/KZM's 30% against KZE's 25% then read again the datasheets, the tests are not the same, runtime and parameters are not the same, in fact datasheets show that the 30% change for KZM was after 8000hrs test, 6000 hrs for KZH and only 3000Hrs for the KZE's 25%, not to mention that all tests were conducted at their respective maximum ratings.
                                  You make an excellent point here, one that I missed, in that due to the massive increase in rated life expectancy of the caps, any loss in percentage change is more than made up for in the smaller arc of the aging curve. Ie. A 6k-8k hrs cap will likely be at, or less than the 25% change noted at the 2k hrs mark when compared to the other series. Correct?


                                  Originally posted by SIDMX
                                  MBZ are pretty good caps but that doesn't mean that they are still good after 12 years without use, they could be good and/or just needing some reforming, however without an ESR meter IMHO the safest/smartest thing to do is to replace them, because deciding by "gut feelings" could put the reliability of your board in jeopardy, but in the end it's your call.
                                  Your comments here prompted me to do some research on this board, as well as via Google on the subject of capacitor reforming, dielectric aging and degradation as well as how It's made in the 1st place. All extremely interesting information, I learned a lot!
                                  My questions are as follows.

                                  The following questions are in reference to known quality brands and series that would otherwise be left alone in a normal recap of a board that hasn't been sitting forever. In this board's case the Rubycons, KZE UCCs, or capacitors otherwise too small to worry about.
                                  How can you test for this aging to be sure that when you fire up the board, you don't blow up the cap(s) with what should be standard voltage and ripple that it would normally handle, but can't due to internal degradation?
                                  Again, known good ones like say the Rubys.
                                  I get the idea that you somehow can't test for this with a simple ESR meter, being that it may test good at low voltage, but fail in service under normal operating voltage.
                                  In other words, how do you determine which caps need reforming and which ones don't? Do you have to remove each one from the circuit before you can attach them to a variable benchtop PSU and slowly ramp up voltage to begin the reforming process?
                                  Do you use AC voltage or DC?

                                  With those questions posed, on to the reality and task at hand.
                                  Being that this board has sat, not in use or powered for 10 years, not 12 and to be on the safe side so as to eliminate any capacitors with a degraded electrolytic oxide, even aside from known bad series/brands that is. Do I have to replace every single electrolytic cap on the board, even the tiniest ones? Or how does that work? Hopefully it makes sense what I'm asking here.


                                  Originally posted by SIDMX
                                  The only way to tell for sure the circuit's ESR tolerances is to actually know the full circuit's operation (or to have previous experiences recaping that board), since the circuit is unknown then the safest option is to match as close as posible the specs of the original caps.
                                  So are the 10v 1,000uf caps best then?
                                  Ie. Going up in voltage from 6.3v is a safe thing, safer than way off spec with the other values which are all spot on or so close it won't matter.
                                  Last edited by y_not; 07-10-2013, 09:21 PM.
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                                    #18
                                    Re: Help verifying cross reference of Junk Caps &lt; Nichicon/Chemi-Con

                                    Any advice on this?
                                    I see a somewhat similar thread was just started, but doesn't quite apply/answer my questions.

                                    Thanks a bunch for looking!
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