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    [help required] which capacitor type for monitor power board

    Hello!

    I need help on picking which capacitors I should buy as a replacement.

    Recently my 26" Samsung 2693HM monitor started to refuse to power on for around 60 seconds until he 'warm up' and then show the screen. I already read all the topics at badcaps forum regarding my monitor model and I finally decided to 'open it' and check whats going on 'inside'.
    I have found one capacitor that leaked. My plan is to change all the capacitors on the power board and not just the one that leaked.





    1st question:
    ==========
    From what I understood, when it comes to capacitors which will be placed on power boards (for power supply) all caps MUST be with Low ESR, correct?




    2nd question:
    ===========
    Here are the caps that I need to change:

    3x 1000uF 35v (12 x 20 mm) - Sam Young NXB
    1x 1000uF 25v (10 x 20 mm) - Sam Young NXB
    2x 2200uF 10v (10 x 25 mm) - Sam Young LXZ

    2x 2.2uF 50v (5 x 11 mm) - Sam Young LXV
    3x 22uF 50v (6 x 11 mm) - Sam Young LXV
    2x 47uF 50v (6 x 11 mm) - Sam Young LXV

    1x 220uF 450v (20 x 40 mm) - can't read the brand



    Here is what I would like to know: I was told that it's good to use a capacitor with the same capacity BUT with little higher rated voltage. For instance for 10v I shpuld pick 16v. I don't know if picking up 25v rated instead 10v rated is good or bad. I also read that using little higher rated voltage could prolong the caps life? Is that true? Someone also told me that using higher voltage rated caps will not damage the monitor BUT monitor will take longer time (than normal) to show the screen (to power on) ? Can someone shed some light on these theories, please?

    Also, if it is ok to put higher voltage caps without any flaws, which voltages would you siggest me considering the list of the caps that I have posted ^ above? Can you please made a note for every specific cap from my list.





    3rd question:
    ===========
    While I'm trying to find the local store that has the caps that I need, I often find the caps which are wider than the original ones. (or if I'm looking at some spare caps with higher voltages, those caps are wider). I know that how wide it is shouldn't make a difference BUT in my case, some original caps are very (VERY) close to each other. Like 1mm close. My fear is that if I put caps wider than original ones, they will make side-contact with each other. I think that would not be good since it will increase the temperature and and make them fail sooner. Am I correct?
    Problem is it's hard to find matching caps here at local store with Low ESR and same dimensions. Unfortunately I can't currently order it online (outside my country) and I don't know anyone here that can order it for me. So I'm kinda stuck at picking from what I can find at local store. But I need advice about caps size and how bad it's for them to have side-contact?

    For instance two caps that are very close to each other are:

    1000uF 35v (12 x 20 mm) - its 12mm wide
    2200uF 10v (10 x 20 mm) - its 10mm wide

    btw ^ 1000uF 35v is the one that leaked and you can see these two caps on the far right on the image I uploaded as an attachment.

    So, these ^ two are very close to each other. Maybe I'm wrong, but could it be that Samsung didn't wanted them to have a contact (by picking higher rated voltage for 2200uF) because it will require wider capacitor, but instead they went with a capacitor which is slim but also rated to smaller voltage?

    You can see these two caps on the far right on the image I uploaded as an attachment.





    4th question:
    ===========
    I read this topic:
    https://www.badcaps.net/forum/showthread.php?t=58648

    It was told that you can put polymer capacitors instead electrolytic ones for fixing a PC motherboard. But what about electrolytic capacitors for monitor power board? Can I also put polymer caps there (instead of electrolytic ones) ? Is it safe?

    If the answer is 'Yes' then should the spare polymer caps (for power board) have the same capacitance and voltage rating or it can (should) be lower? (I'm asking this because that is also mentioned in the topic I linked ^ above)


    Thanks in advance for your help!

    ... and sorry about the long post.
    Attached Files

    #2
    Re: [help required] which capacitor type for monitor power board

    polymer in power boards is 50/50
    unless you have patience & test gear you shouldnt try it.

    as for make/series.
    i use panasonic FR for anything under 100v
    for high voltage the only 2 reliable brands with much available are nichicon and rubycon.

    Comment


      #3
      Re: [help required] which capacitor type for monitor power board

      Thanks for your reply stj.

      Unfortunately none of 'big 4' (Rubycon, Sanyo, Nichicon or Panasonic) are available here. I get to pick between samwha, yageo, jamicon, or some non-name caps. I've only managed to find on local shop site 2 caps from panasonic that match some quality. Those are:
      2.2uF 50v 5x11 105c Low ESR - Panasonic FC
      and
      22uF 50v 5x11 105c Low ESR - Panasonic FC

      ^are these (Panasonic FC) good ones?


      As for the rest of caps that I need, I just can't find them here at local shops. Even when I find the specs that I'm looking for, brand is unknown, or somethong like Jamicon. Btw how bad is Jamicon compared to Sam Young which was on my monitor power board for almost 9 year and worked without issues (until recently) ?


      One more thing... may I use ULTRA Low ESR spare caps instead of the original caps from my monitor power board? I mean could 'ultra low esr' caps create some malfunction if used for monitor power board?
      Last edited by twist3r; 10-10-2017, 01:46 AM.

      Comment


        #4
        Re: [help required] which capacitor type for monitor power board

        fc are the best of what you listed.
        i doubt you can get real "ultra-low esr" caps, hardly any are made any more - that's where poymers come in.

        Comment


          #5
          Re: [help required] which capacitor type for monitor power board

          I believe Samyoung is or was producing Nippon Chemicon parts. The LXZ series parts are basically equivalent to Panasonic FC series. The LXV parts are the design generation before LXZ, so FC series parts are better, but not so much better that they are likely to cause a problem.

          The Samyoung NXB series seems similar to the Nippon Chemicon KY or KZE series. If that supplier has Panasonic FM series parts those would probably work.
          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 required] which capacitor type for monitor power board

            Thank you @stj and @PeteS in CA, for your replies!

            While I was searching local shop sites I also wanted to check what would be a good pick in ('perfect') situation like when/if the local shop had everything I needed/wanted to buy.
            So I visited UK Farnell website and tried to find which caps I would pick in perfect situation.

            What do you guys think if I would pick Rubycon ZLJ (or ZLH) series caps? Would these series be good for power board of my monitor?

            'On paper' it sais that 'they could last' 6000-10000 hours, have high max ripple current and low impedance (like 0.028 or 0.018). From my beginners point of view I would say these two Rubycon series (ZLJ and ZLH) would be good, but I would like to hear what experienced guys like you think?

            I read somewhere that ultra high ripple current is not that good for power suplies (so I thought that applies also to caps for monitor power boards). Can you shed some light on this, please?


            Also, when I compared two caps (same capacitance and voltage ratings) from two different cap series (ZLH and ZLJ) I'm in confusion which is better?

            ------
            ZLH/1000uF/25v/10x23/ has 0.018 impedance but 2250mA ripple current
            ZLJ/1000uF/25v/10x20/ has 0.028 impedance but 2500mA ripple current


            or


            ZLH/2200uF/10v/10x23/ has 0.018 impedance but 2250mA ripple cirrent
            ZLJ/2200uF/10v/10x25/ has 0.024 impedance but 2900mA ripple current

            ------

            The difference, wnen I compare what is stated on paper for both series, is that ZLH has 'long life, low impedance' and ZLJ has also 'long life, low impedance' BUT as a plus it has also 'high ripple current'.

            On ZLJ pdf data sheet it sais 'upgrade' so I think ZLJ might be an upgraded version of 'older' ZLH series, and ZLJ should be a better pick (for monitor power board recap). Am I correct?


            Sorry again for a long post. And thanks in advance for your help!

            Comment


              #7
              Re: [help required] which capacitor type for monitor power board

              Originally posted by twist3r View Post
              1st question:
              ==========
              From what I understood, when it comes to capacitors which will be placed on power boards (for power supply) all caps MUST be with Low ESR, correct?
              Yes, low ESR is correct.
              That said, there are many different "variations" of low ESR. Typically, these are entry-level low ESR, very low ESR, and ultra low ESR. What you use will depend on what you are recapping.

              Old computer ATX power supplies typically take entry-level and very low ESR.
              Newer ATX PSUs are better suited towards very low ESR, with some accepting even ultra low ESR.
              Flyback topology-based power supplies (such as CRT monitors, LCD monitors, portable power adapters, TVs, and amplifier PSs) also usually work best with very low ESR and can sometimes take ultra low ESR.
              Depending on the PSU you are repairing,

              Originally posted by twist3r View Post
              2nd question:
              ... I was told that it's good to use a capacitor with the same capacity BUT with little higher rated voltage. For instance for 10v I shpuld pick 16v.
              No, that's not necessary at all.

              This trick was used mostly back in the days when low ESR caps weren't that popular. The reason being is that when you increase the voltage rating of a cap while still maintaining the same capacitance, the physical size of the capacitor also increases. And when it comes to capacitors, ESR and ripple current are actually a function of the capacitor's physical size. So bigger cap = lower ESR = higher ripple current capability.

              Nowadays, you no longer need to do that, as there are all kinds of low ESR capacitors, and you can find one for just about any application.

              So in short, it's not needed to use a higher voltage capacitor. You'd just be wasting money. Moreover, with high voltage capacitors being bigger, you may not be able to find proper substitute capacitors for your monitor due to size constraints.

              Originally posted by twist3r View Post
              Someone also told me that using higher voltage rated caps will not damage the monitor BUT monitor will take longer time (than normal) to show the screen (to power on) ? Can someone shed some light on these theories, please?
              That is quite wrong. Whoever told you this - don't ask them for more electronics advice.
              I mean, no offense to them.

              Originally posted by twist3r View Post
              3rd question:
              ===========
              While I'm trying to find the local store that has the caps that I need, I often find the caps which are wider than the original ones. (or if I'm looking at some spare caps with higher voltages, those caps are wider). I know that how wide it is shouldn't make a difference BUT in my case, some original caps are very (VERY) close to each other. Like 1mm close. My fear is that if I put caps wider than original ones, they will make side-contact with each other. I think that would not be good since it will increase the temperature and and make them fail sooner. Am I correct?
              Well, in a monitor power supply, a wider cap will block more air from getting in / exiting out of the monitor. So yes, you don't want really big caps that will block everything. At the same time, bigger capacitors (within each cap series) are rated for lower ESR and higher ripple current (and sometimes also longer endurance life), so in some cases it is okay to use bigger ones. I usually don't do it unless I really have lots of space inside the monitor.

              Originally posted by twist3r View Post
              4th question:
              ===========
              I read this topic:
              https://www.badcaps.net/forum/showthread.php?t=58648

              It was told that you can put polymer capacitors instead electrolytic ones for fixing a PC motherboard. But what about electrolytic capacitors for monitor power board? Can I also put polymer caps there (instead of electrolytic ones) ? Is it safe?
              No, most PSUs are not designed to handle polymer capacitors.
              You might also have a hard time finding 25V and 35V polymer capacitors for your monitor.

              So it is NOT recommended.

              The reason polymer capacitors work in a motherboard is because most of the time they are used on DC-DC buck-converter circuits. Most buck-converter circuits are typically designed to switch at very high frequency (typically at least 2-4 times higher than a normal ATX PSU), so the ESR of the output capacitors tends to matter even more than just the capacitance itself.

              And on PC motherboards, most of the main voltages (CPU, RAM, chipset) are usually well below 3V (on modern stuff, they are well below 2V). So that's why one can often replace 6.3V electrolytic caps with 2.5V and 4V polymers without issue. Of course, before doing this, one has to verify that the 2.5V and 4V polymers won't be connected to some higher voltage rail (such as 5V), which will instantly blow the caps.

              Originally posted by twist3r
              Unfortunately none of 'big 4' (Rubycon, Sanyo, Nichicon or Panasonic) are available here.
              What about United Chemicon?

              If not, feel free to send a Private Message to member Behemot here. He sells caps and is based in Europe (Czech Republic), so shipping may not be that bad.

              Originally posted by twist3r
              I get to pick between samwha, yageo, jamicon, or some non-name caps.
              Well between those choices, I'd probably go with SamWha and Yageo first, provided you can find some low ESR series. Jamicon is very "so-so", and I'm not sure you'd get a lasting repair with them inside a hot LCD monitor power supply.

              As for no-name China/Taiwan cap brands - definitely avoid those.

              Originally posted by twist3r
              I've only managed to find on local shop site 2 caps from panasonic that match some quality. Those are:
              2.2uF 50v 5x11 105c Low ESR - Panasonic FC
              and
              22uF 50v 5x11 105c Low ESR - Panasonic FC

              ^are these (Panasonic FC) good ones?
              Panasonic FC series are excellent for PSU use, as are their FK, FR, FM, and FS series. NHG is their general purpose series rated for 105C - these are not low ESR, but still waaay better than SamWha, Yageo, and Jamicon.

              Originally posted by twist3r
              Btw how bad is Jamicon compared to Sam Young which was on my monitor power board for almost 9 year and worked without issues (until recently) ?
              I'd say overall worse. Maybe better than a no-name cheap brand, but not better than Sam Young.

              The thing about cheap capacitors (that means every non-major non-Japanese brand) is that you never know what you will get in terms of quality. Sometimes you get lucky and the cheap caps last many years like your San Youngs. Sometimes you don't, and they die in a year or two.

              Originally posted by twist3r
              One more thing... may I use ULTRA Low ESR spare caps instead of the original caps from my monitor power board? I mean could 'ultra low esr' caps create some malfunction if used for monitor power board?
              Do you mean ultra-low ESR electrolytic caps from a motherboard (like Nichicon HM/HN/HZ, Rubycon MBZ/MCZ, and Panasonic FL/FJS)??

              I have tried it more than a few times in random LCD TV and monitor PSUs, and it usually works just fine. The only side effect is you may get some audible coil whine from the monitor's PSU. That's usually nothing to worry about, but you may find it annoying, so that's why I am mentioning this.

              Originally posted by twist3r
              What do you guys think if I would pick Rubycon ZLJ (or ZLH) series caps? Would these series be good for power board of my monitor?
              Rubycon ZLJ is excellent for PSU use!
              ZLH should also work fine in LCD monitor/TV PSUs. May be a bit too low for ATX PSU, though.

              Originally posted by twist3r
              'On paper' it sais that 'they could last' 6000-10000 hours,
              That's at their maximum rated temperature (105C) and other ratings maxed out. Inside a monitor, things usually run at 50-70C. So the lower temperature alone will increase the cap's lifetime many times over.
              After all, a year has over 8000 hours - yet many caps last longer than that. And the above I posted is the reason why.

              Originally posted by twist3r
              The difference, wnen I compare what is stated on paper for both series, is that ZLH has 'long life, low impedance' and ZLJ has also 'long life, low impedance' BUT as a plus it has also 'high ripple current'.

              On ZLJ pdf data sheet it sais 'upgrade' so I think ZLJ might be an upgraded version of 'older' ZLH series, and ZLJ should be a better pick (for monitor power board recap). Am I correct?
              ZLH is just a lower ESR version of ZLJ, hence the "upgrade" rating. But for PSU use, ZLJ is probably slightly more preferable over ZLH due to slightly higher ESR. Both will work just fine, though.

              Hope this answers some of your questions.
              Last edited by momaka; 10-10-2017, 11:24 PM.

              Comment


                #8
                Re: [help required] which capacitor type for monitor power board

                O. M. G.

                I admit that I tend to create a very long posts, but that is only because I'm trying to ask all the questions that interest me, in one post, so that the person that decides to answer will have all the questions in a single (or sometimes in a few) of my post(s).

                But I wasn't expecting that I will get an answer like this, loaded with the informations that I was looking for.

                I am speechless.

                THANK YOU @momaka !!!
                Last edited by twist3r; 10-11-2017, 12:10 AM.

                Comment


                  #9
                  Re: [help required] which capacitor type for monitor power board

                  tl;dr:
                  I have listed caps that I'm considering for my monitor power board recapping. Mostly I'm asking for your opinions about my choices (they are in bold). But I also have some dilemmas and trouble to figure out some things and that is why text is so large. I'm sorry for that. It took me 6 hours to write it on 7" tablet. (if you have a will for it) you can read it faster than what it took me tp write it. Otherwise just completely ignore this post. Again sorry for this large post.

                  ========

                  I've managed to find one shop in my country which can order the caps I want from either UK Farnell or Digikey. Bad thing is it will probably be very pricey. ... Oh well.

                  Anyway, heres is what I've come out with while I'm trying to figure out which caps to order. I'm trying to pick between Rubycon, Panasonic and Nichicon.


                  capacitor | size | ripple current | impedance | life | brand

                  1000uF 35v | 12.5 x 20 | 2360mA | 0.021 | 5000 hrs | Sam Young NXB
                  ------------------------------------------------------------------------------------------------------------------------
                  1000uF 35v | 12.5 x 20 | 2480mA | 0.017 | 10000 hrs | Rubycon ZLH
                  1000uF 35v | 12.5 x 20 | 2600mA | 0.018 | 10000 hrs | Panasonic FR


                  1000uF 35v | 12.5 x 20 | 2600mA | 0.025 | 10000 hrs | Rubycon ZLJ

                  ^ At first I wanted Rubycon ZLJ but even though this capacitor is listed in Rubycon ZLJ data sheets it seams like it never existed since nobody is selling it (digikey, uk farnell).


                  1000uF 35v | 12.5 x 25 | 3190mA | 0.015 | 7000 hrs | Panasonic FM

                  ^ My 2nd initial choice was FM series from Panasonic, but it's height is 5mm higher, and since I'm trying to match the original height I've dropped it from my choice list. I know height can be higher, its just that I'm trying to match the original as best as I can. What I can't pick is caps (especially the larger ones) which has larger diameter than the original ones since that would make caps touch each other on the side.

                  Low impedance values scares me and here is why:
                  One of my biggest concerns is that, while I'm trying to find the same (or better) match, is what @momaka said. If I understood him correctly, I can go with lower impedance (ESR) and it should work, BUT it may happen that my monitor start to produce annoying fuzzing noise. I don't know what is considered 'a very low ESR' when it comes to picking a capacitor which will be put on (monitor) power board so that it will work great BUT without creating fuzzing noise. This dilemma is extremely present while I'm trying to pick a proper spare caps of very small capacitance (you'll notice it at the bottom of this post). So, can someone, please, check ESR ratings from my caps choice list from this post, and let me know which ones (probably) shouldn't create a fuzzing noise?



                  1000uF 25v | 10 x 20 | 1900mA | 0.025 | 4000 hrs | Sam Young NXB
                  ------------------------------------------------------------------------------------------------------------------------
                  1000uF 25v | 10 x 20 | 2500mA | 0.028 | 10000 hrs | Rubycon ZLJ
                  1000uF 25v | 10 x 23 | 2250mA | 0.018 | 10000 hrs | Rubycon ZLH
                  1000uF 25v | 10 x 20 | 2180mA | 0.020 | 10000 hrs | Panasonic FR


                  1000uF 25v | 12.5 x 20 | 2600mA | 0.018 | 5000 hrs | Panasonic FM

                  ^ I've also checked the stats of Panasonic FM but its diameter is 12.5mm so that's a 'no'. (also projected life span is 'only' 5000 hrs compared to other three mantioned above)

                  btw. does it matter if the cap I pick has impedance little higher than the original one? Like in this case 0.004 higher? (my first pick)




                  2200uF 10v | 10 x 25 | 1660 mA | 0.038 | 5000 hrs | Sam Young NXP (LXZ)
                  ------------------------------------------------------------------------------------------------------------------------
                  2200uF 10v | 10 x 25 | 2900mA | 0.024 | 10000 hrs | Rubycon ZLJ
                  2200uF 10v | 10 x 23 | 2250mA | 0.018 | 10000 hrs | Rubycon ZLH
                  2200uF 10v | 10 x 25 | 2470mA | 0.018 | 10000 hrs | Panasonic FR

                  ^^^^ The original cap on my monitor power board has a size of 10x25mm which I couldn't find listed in Sam Young data sheets. So I'm going here on 'auto pilot' when it comes to ripple current and impedance. (there was only one with 12.5x20mm in size). So I listed ripple current and impedance values of that one from Sam Young data sheets (the 12.5x20mm one). (I guess they are 'kinda' approximate to the cap on my monitor power board which is 10x25 in size)

                  Also cap from Panasonic FM series has 12.5mm diameter so I couldn't consider it.




                  This one down here is from my monitor inverter board which I would like to buy just in case I need it.

                  220uF 35v | 8 x 15 | 995mA | 0.056 | 3000 hrs | UCC KZE
                  ------------------------------------------------------------------------------------------------------------------------
                  220uF 35v | 8 x 16 | 1600mA | 0.059 | 10000 hrs | Rubycon ZLJ
                  220uF 35v | 8 x 15 | 1240mA | 0.041 | 3000 hrs | Panasonic FM


                  220uF 35v | 8 x 11.5 | 945mA | 0.056 | 8000 hrs | Rubycon ZLH
                  220uF 35v | 8 x 11.5 | 950mA | 0.056 | 6000 hrs | Panasonic FR

                  ^ As a total newbie I think that 'maybe' even these two could be used, but I'm not sure since rated current ripple is even lower than the value of original cap. (and all that considering it is for caps on inverter board)



                  Ok, back to the caps for monitor power board. For next three capacitance (47uF, 22uF and especially 2.2uF) I'm partially or completely lost.

                  47uF 50v | 6.3 x 11.0 | 300mA | 0.56 | 2000 hrs | Sam Young NXL (LXV)
                  ------------------------------------------------------------------------------------------------------------------------
                  47uF 50v | 6.3 x 11.0 | 300mA | 0.43 | 2000 hrs | Nichicon PW
                  47uF 50v | 6.3 x 11.2 | 405mA | 0.14 | 5000 hrs | Panasonic FR
                  47uF 50v | 6.3 x 11.2 | 295mA | 0.30 | 5000 hrs | Rubycon YXJ
                  47uF 50v | 6.3 x 11.0 | 260mA | 0.60 | 0000 hrs | Panasonic FC

                  ^ Nichicon PW matches the original cap nicely, BUT the issue is that UK Farnell doesn't have it. They have it only in their USA storage facility and that would even more increase the cost (for ~16 extra British pounds only for shipping that cap to UK from USA). Digikey has it but then again (of course) Digikey doesn't have some other caps which I only found at UK Farnell so I'm 'stretched' while trying to determ what choice to make when it comes to some capacitors.

                  I also like Panasonic FR cap. It has higher ripple current and lower impedance (ESR) than the original cap. BUT as I mantioned already it scares me such lower ESR (compared to original cap) because, since I'm a newbie, I feer that low ESR may produce annoying fuzzing noice from my monitor that @momaka mantioned in his post. Can someone tell me how low for ESR I can go and be sure that it will not create already mantioned annoying fuzzing noise?

                  ^ The other two cap choices (3rd YXJ and 4th FC) are also something I'm considering but again values are not maching original cap. Rubycon YXJ is closer to original value with only 5mA lower ripple current and lower ESR, but I don't know if I'm safe with that one because of lower ripple current. Btw. is YXJ good Rubycon series?
                  4th choice is Panasonic FC cap. I know it's a good cap series, but considerable lower ripple current (by 40mA) and even little higher ESR (0.60 Ohms) stops me from putting it higher on my consideration list.




                  22uF 50v | 6.3 x 11 | 180mA | 0.91 | 2000 hrs | Sam Young NXL (LXV)
                  ------------------------------------------------------------------------------------------------------------------------
                  22uF 50v | 5.0 x 11 | 238mA | 0.34 | 2000 hrs | Rubycon ZL
                  22uF 50v | 5.0 x 11 | 250mA | 0.34 | 2000 hrs | Panasonic FM
                  22uF 50v | 5.0 x 11 | 250mA | 0.34 | 5000 hrs | Panasonic FR
                  22uF 50v | 5.0 x 11 | 238mA | 0.34 | 2000 hrs | Nichicon HD

                  ^Here (for some reason) I wanted to pick Rubycon ZL cap, even though values at Panasonic caps are better. Maybe I wanted ZL as my first choice because initially I wanted all the spare caps to be from one brand, but it seams like thats notngonna happen. The 'problem' (for me) with Rubycon ZL cap isbthat UK Farnell has it but not Digikey (why it always has to be one cap that 'ruins' the whole plan? ) Is ZL series abandoned?

                  Also... (again) there is that thing about considerable lower impedance (ESR) for all spare caps compared to original one. Will they make my monitor produce annoying fuzzing noise?

                  btw. among all 4 caps from the list ^above, Nichicon HD is most expensive one. Any reason for that? Is it a good cap (the HD series)?
                  Last edited by twist3r; 10-14-2017, 10:38 AM.

                  Comment


                    #10
                    Re: [help required] which capacitor type for monitor power board

                    ^ continued (it was too long post)


                    ====



                    And... here we are, the smallest capacitance (2.2uF), which makes my head overload for days.
                    The reason for that is that in Sam Young NXL (LXV) data sheets it isn't listed at all. Like they never manufactured it. Capacitor from my monitor power board has markings of Sam Young LXV but since I've only found data sheets for NXL (LXV) I guess that Sam Young at some point (after 2008. year) 'rebranded' the LXV serie into NXL. And now old (LXV) data sheets are lost and there is only new one, the NXL (LXV).
                    Because of this 'mess' I dont know and can't figure out the values for this (THIS) little...
                    And to make things even worse, the values I managed to find among the caps that I would try to consider as spare ones are all over the place (none of them are closed to each other).
                    And... at the top of all this... again... that fear for possible annoying fuzzing noise if the ESR is too low, but at the other hand other spare caps has high ESR which may be even higher than original one (which I cant find values for in Sam Young specs).

                    So, can someone tell me which values I should go for on the list below. Also if someone can 'guess' possible value (ripple current and impedance) of the original cap from my monitor power board that would be great. The best would be if someone has an old Sam Young LXV data sheet.


                    2.2uF 50v | 5 x 11 | XXmA | X.X | XXXX hrs | Sam Young NXL (LXV)
                    ------------------------------------------------------------------------------------------------------------------------
                    2.2uF 50v | 5 x 11 | 45mA | 1.8 | 1000 hrs | Panasonic FC
                    2.2uF 50v | 5 x 11 | 43mA | 2.5 | 5000 hrs | Rubycon YXJ
                    2.2uF 50v | 5 x 11 | 55mA | 3.0 | 2000 hrs | Nichicon UPW

                    I would pick Panasonic FC because of low impedance. But isn't it too low? Remember, I'm trying to find the one that would match the original but also not produce annoying fuzzing noise. At the other hand Rubicon YXJ offers a possible 5000 hours life span compared to FC cap (1000 hrs), but impedance of Rubycon YXJ cap is 2.5 Ohms. Nichicon UPW offers best ripple current specs but his impedance is 3.0 Ohms.
                    I'm completely lost here. I have no idea at all which one should I pick. As a newbie it's hard for me to determ original values of original 2.2uF 50v cap since data sheet doesn't list it.

                    btw. did Nichicon rebranded PW serie into UPW? (at first glance the specs look the same to me)




                    ===

                    The last question is about the largest capacitor from my monitor power board. It doesn't stand on the board but it is laying down horizontally on the board. I can't read the brand and series markings, but it's rated at 220uF 450v. It is (by far) the largest capacitor on my monitor power board. I was told that its probably ok and that I should only recap the other 13 (smaller ones). So what do you guys think? Should I recap that big one too? If 'yes' then which series are good pick for such a large capacitor that is located on power board?

                    Comment


                      #11
                      Re: [help required] which capacitor type for monitor power board

                      Alright, let me try to simplify this for you a little bit.

                      Put it this way: electrolytic caps have pretty lousy tolerances. Capacitance can vary by as much as 20%, so most circuits are usually designed to handle even bigger variations (in many cases, even half the capacitance or two times the capacitance will not break the circuit - though I never suggest going lower than 20% in capacitance than the original).

                      ESR? It can vary quite a bit with temperature - sometimes as much as 2 to 3 times higher at -10°C compared to normal room temperature of 20°C. Also, the ESR of caps decreases as the temperature increases. In a mildly warm PSU, the temperatures can easily reach 40-50°C and in hotter ones (like LCD monitors), 60-70°C is not uncommon either. So you can imagine what happens to the ESR - it drops quite a bit from the value you see in the data sheet. Thus, most devices are usually designed to work with caps over fairly wide ESR variations.

                      From what I've seen, typically PSUs don't start to buzz/whine until the ESR is either increased or decreased by approximately 5 to 10 times the ESR of the original caps. And this applies only to the fairly big output caps - i.e. 470 uF and up. For the very small capacitors (under 100 uF), you can pretty much ignore the datasheets when it comes to power supply recapping (just throw them an eye, but don't worry about matching things too much). So go with whatever low ESR capacitor you can find the cheapest and the easiest. The following are all fine choices for small capacitors (and big ones too, but for those, do check the datasheets):
                      Nichicon (PW, PS, PM, PJ, HE)
                      Rubycon (YXJ, YXG, YXF, ZL, ZLH, ZLJ)
                      Panasonic (FC, FK, FR, FM, FS)
                      United Chemicon (LXV, LXZ, KY, KYB, KZE)

                      What about ripple current? Well, ripple current is the amount of AC current the cap can take before it overheats internally (which over time will cause the cap to fail). Thus if you use caps with lower ripple current ratings, you could technically make your new caps overheat. However, a good circuit design should never be made to stress caps near their maximum ripple current. Therefore, it's usually not a big deal if your new caps have 5-10% lower ripple current. In fact, you will be okay most of the time even with 20% lower ripple current (but try not to do it, *if* possible).

                      That said, the only reason why it's always suggested to have new caps meet or exceed the ripple current rating of the originals is because there is no easy way to measure ripple current in a circuit without expensive equipment. Thus, to avoid running into a situation where the circuit might have been stressing the original caps near their maximums, it just makes more sense to go with caps that can handle more ripple current.

                      Originally posted by twist3r View Post
                      I don't know what is considered 'a very low ESR' when it comes to picking a capacitor which will be put on (monitor) power board so that it will work great BUT without creating fuzzing noise. This dilemma is extremely present while I'm trying to pick a proper spare caps of very small capacitance (you'll notice it at the bottom of this post). So, can someone, please, check ESR ratings from my caps choice list from this post, and let me know which ones (probably) shouldn't create a fuzzing noise?
                      So to answer that question more directly, as long as your new capacitors have ESR that is NOT 5 times lower or higher than the original caps, your monitor likely won't buzz/whine.

                      Also, I think I might have scared you a bit too much about the PSU making buzzing/whining noises, so let me give you an example.

                      In my case, I had a 19" LCD monitor with an FSP PSU that used CapXon KM capacitors. CapXon KM are general purpose capacitors (they don't even list ESR in their datasheet). I went with Panasonic FM for my replacements, so the ESR of those was many times lower than the CapXon KM. Result: monitor worked, but it made a faint whining noise. How loud? Loud enough that I can hear it in the room if there was no other noise whatsoever (think of a quiet winter day). But with the computer turned on, I couldn't hear the monitor over it. As a comparison, let's say the whining noise was about the same or less than a high-pitched whine from a CRT TV.
                      That LCD monitor has been in service for several years now without issues whatsoever. Also, as my new caps aged in the monitor, the whining noise has gone down a bit. So it's not really a big issue. Just avoid doing crazy things like sticking polymers in a power supply that had general purpose caps originally.

                      With that said, let me address your other question individually in another post, though I think this one should have the information you need to make your choices now (that is, not worry so much)
                      Last edited by momaka; 10-14-2017, 12:10 PM.

                      Comment


                        #12
                        Re: [help required] which capacitor type for monitor power board

                        Originally posted by twist3r View Post
                        capacitor | size | ripple current | impedance | life | brand

                        1000uF 35v | 12.5 x 20 | 2360mA | 0.021 | 5000 hrs | Sam Young NXB
                        -------------------------------------------------------------------------
                        1000uF 35v | 12.5 x 20 | 2480mA | 0.017 | 10000 hrs | Rubycon ZLH
                        1000uF 35v | 12.5 x 20 | 2600mA | 0.018 | 10000 hrs | Panasonic FR


                        1000uF 35v | 12.5 x 20 | 2600mA | 0.025 | 10000 hrs | Rubycon ZLJ

                        ^ At first I wanted Rubycon ZLJ but even though this capacitor is listed in Rubycon ZLJ data sheets it seams like it never existed since nobody is selling it (digikey, uk farnell).


                        1000uF 35v | 12.5 x 25 | 3190mA | 0.015 | 7000 hrs | Panasonic FM

                        ^ My 2nd initial choice was FM series from Panasonic, but it's height is 5mm higher, and since I'm trying to match the original height I've dropped it from my choice list. I know height can be higher, its just that I'm trying to match the original as best as I can.
                        Don't worry about matching the size exactly. As long as it will fit in your monitor, it shouldn't matter that much.

                        That said, bigger caps will take and dissipate more heat from the board. So if you have a hot spot on the board with caps in it, using bigger caps will actually help to cool down the board. It's a good design tactic to cool down spots that don't have any other means of cooling.

                        Originally posted by twist3r View Post
                        1000uF 25v | 10 x 20 | 1900mA | 0.025 | 4000 hrs | Sam Young NXB
                        --------------------------------------------------------------------------
                        1000uF 25v | 10 x 20 | 2500mA | 0.028 | 10000 hrs | Rubycon ZLJ
                        1000uF 25v | 10 x 23 | 2250mA | 0.018 | 10000 hrs | Rubycon ZLH
                        1000uF 25v | 10 x 20 | 2180mA | 0.020 | 10000 hrs | Panasonic FR

                        ...
                        does it matter if the cap I pick has impedance little higher than the original one? Like in this case 0.004 higher? (my first pick)
                        Nope.
                        That's a little over 10% variation, but still not like 2 times higher or lower, so it very likely won't matter. If you really want to be safer, then go with the Panasonic FR.

                        Originally posted by twist3r View Post
                        2200uF 10v | 10 x 25 | 1660 mA | 0.038 | 5000 hrs | Sam Young NXP (LXZ)
                        -------------------------------------------------------------------------
                        2200uF 10v | 10 x 25 | 2900mA | 0.024 | 10000 hrs | Rubycon ZLJ
                        2200uF 10v | 10 x 23 | 2250mA | 0.018 | 10000 hrs | Rubycon ZLH
                        2200uF 10v | 10 x 25 | 2470mA | 0.018 | 10000 hrs | Panasonic FR

                        ^^^^ The original cap on my monitor power board has a size of 10x25mm which I couldn't find listed in Sam Young data sheets. So I'm going here on 'auto pilot' when it comes to ripple current and impedance. (there was only one with 12.5x20mm in size). So I listed ripple current and impedance values of that one from Sam Young data sheets (the 12.5x20mm one). (I guess they are 'kinda' approximate to the cap on my monitor power board which is 10x25 in size)
                        Within a capacitor series, ESR and ripple current are a function of the case size. So if you look in the Sam Young NXP datasheet, you can get the ESR and ripple information out of any other cap that has the same 10x25 mm can size, regardless of the voltage or capacitance. The 10V, 1500 uf cap they have matches the can size, so the ESR and ripple current you are looking for is 45 mOhms ESR and 1440 mA ripple current. That said, the above cap choices should still work okay.

                        Originally posted by twist3r View Post
                        220uF 35v | 8 x 15 | 995mA | 0.056 | 3000 hrs | UCC KZE
                        ----------------------------------------------------------------------
                        220uF 35v | 8 x 16 | 1600mA | 0.059 | 10000 hrs | Rubycon ZLJ
                        220uF 35v | 8 x 15 | 1240mA | 0.041 | 3000 hrs | Panasonic FM

                        220uF 35v | 8 x 11.5 | 945mA | 0.056 | 8000 hrs | Rubycon ZLH
                        220uF 35v | 8 x 11.5 | 950mA | 0.056 | 6000 hrs | Panasonic FR

                        ^ As a total newbie I think that 'maybe' even these two could be used, but I'm not sure since rated current ripple is even lower than the value of original cap. (and all that considering it is for caps on inverter board)
                        Yup.

                        Originally posted by twist3r View Post
                        Ok, back to the caps for monitor power board. For next three capacitance (47uF, 22uF and especially 2.2uF) I'm partially or completely lost.

                        47uF 50v | 6.3 x 11.0 | 300mA | 0.56 | 2000 hrs | Sam Young NXL (LXV)
                        ------------------------------------------------------------------------
                        47uF 50v | 6.3 x 11.0 | 300mA | 0.43 | 2000 hrs | Nichicon PW
                        47uF 50v | 6.3 x 11.2 | 405mA | 0.14 | 5000 hrs | Panasonic FR
                        47uF 50v | 6.3 x 11.2 | 295mA | 0.30 | 5000 hrs | Rubycon YXJ
                        47uF 50v | 6.3 x 11.0 | 260mA | 0.60 | 0000 hrs | Panasonic FC

                        ^ Nichicon PW matches the original cap nicely, BUT the issue is that UK Farnell doesn't have it.
                        For small caps like this, I wouldn't even bother to look twice. Any of the caps you have listed should be fine, though Rubycon YXJ and Panasonic FC may be the slightly better choices, simply because they are pretty much designed for PSU use (especially FC).

                        Originally posted by twist3r View Post
                        Btw. is YXJ good Rubycon series?
                        Yes!

                        Originally posted by twist3r View Post
                        22uF 50v | 6.3 x 11 | 180mA | 0.91 | 2000 hrs | Sam Young NXL (LXV)
                        ------------------------------------------------------------------------
                        22uF 50v | 5.0 x 11 | 238mA | 0.34 | 2000 hrs | Rubycon ZL
                        22uF 50v | 5.0 x 11 | 250mA | 0.34 | 2000 hrs | Panasonic FM
                        22uF 50v | 5.0 x 11 | 250mA | 0.34 | 5000 hrs | Panasonic FR
                        22uF 50v | 5.0 x 11 | 238mA | 0.34 | 2000 hrs | Nichicon HD

                        ^Here (for some reason) I wanted to pick Rubycon ZL cap, even though values at Panasonic caps are better. Maybe I wanted ZL as my first choice because initially I wanted all the spare caps to be from one brand, but it seams like thats notngonna happen.
                        Nah, no need to do brand matching, unless you have some kind of OCD. I personally like to keep my cap repairs "diverse". In fact, sometimes I even do it on purpose - see how many different (good) Japanese brands I can fit on the same device.

                        The truth is, it doesn't really matter. Just go with cheapest and most easily available.

                        Originally posted by twist3r View Post
                        btw. among all 4 caps from the list ^above, Nichicon HD is most expensive one. Any reason for that? Is it a good cap (the HD series)?
                        Nichicon HD series are rather old now, and they are also based on fairly aqeous electrolyte. So personally, I don't recommend them much for PSU use, especially in hot LCD monitors. Nichicon HD is more or less equivalent to Rubycon ZL and Chemicon KZE, but I think ZL and KZE are a bit more robust for PSU use.

                        Originally posted by twist3r View Post
                        2.2uF 50v | 5 x 11 | XXmA | X.X | XXXX hrs | Sam Young NXL (LXV)
                        -------------------------------------------------------------------------
                        2.2uF 50v | 5 x 11 | 45mA | 1.8 | 1000 hrs | Panasonic FC
                        2.2uF 50v | 5 x 11 | 43mA | 2.5 | 5000 hrs | Rubycon YXJ
                        2.2uF 50v | 5 x 11 | 55mA | 3.0 | 2000 hrs | Nichicon UPW

                        I would pick Panasonic FC because of low impedance. But isn't it too low? Remember, I'm trying to find the one that would match the original but also not produce annoying fuzzing noise. At the other hand Rubicon YXJ offers a possible 5000 hours life span compared to FC cap (1000 hrs), but impedance of Rubycon YXJ cap is 2.5 Ohms. Nichicon UPW offers best ripple current specs but his impedance is 3.0 Ohms.
                        I'm completely lost here. I have no idea at all which one should I pick. As a newbie it's hard for me to determ original values of original 2.2uF 50v cap since data sheet doesn't list it.
                        Any of the ones you listed will do.

                        Remember, when in doubt, just pick a capacitor series from that list I made in the above post.

                        Originally posted by twist3r View Post
                        btw. did Nichicon rebranded PW serie into UPW? (at first glance the specs look the same to me)
                        PW is the same as UPW.

                        I think it's just related to the part number, as the part number for all Nichicon series starts with the letter U... so you get UPW, UPS, UKA, UVZ.... But really everyone here still knows them series without the U in front (i.e. PW, PS, KA, VZ, etc.).

                        Originally posted by twist3r View Post
                        The last question is about the largest capacitor from my monitor power board. It doesn't stand on the board but it is laying down horizontally on the board. I can't read the brand and series markings, but it's rated at 220uF 450v. It is (by far) the largest capacitor on my monitor power board. I was told that its probably ok and that I should only recap the other 13 (smaller ones). So what do you guys think? Should I recap that big one too? If 'yes' then which series are good pick for such a large capacitor that is located on power board?
                        In most cases, it is okay to leave it, as that capacitor is not under a lot of stress. But if you really care about this LCD monitor and just want to know that the PSU will never give you issues, then you can replace it.

                        The only times I consider replacing primary caps is if they are CapXon, as I've seen a few on the forums here go completely open circuit. Don't recall if there are any other brands that did it.

                        If you do replace it, then you need NOT look for low ESR replacements. Any 85C or 105C rated capacitor will do. Though, since this is for an LCD monitor PSU where things can get hot, I do recommend going with a 105C-rated cap. Just keep in mind that if you do replace that cap, it will be costly - typically $3-6 just for that cap alone.

                        Originally posted by twist3r View Post
                        But I also have some dilemmas and trouble to figure out some things and that is why text is so large. I'm sorry for that. It took me 6 hours to write it on 7" tablet.
                        WOW! You have some patience, man!
                        I would go crazy if someone asks me to write anything more than a few sentences on any touchscreen device.

                        FYI, it took me maybe 40-45 minutes total for these two posts here. And all of that on a laptop with a trackpad. If I was on my desktop, it would be even less. That's one reason I'll never let go of my desktops.
                        Last edited by momaka; 10-14-2017, 12:57 PM.

                        Comment


                          #13
                          Re: [help required] which capacitor type for monitor power board

                          WOW @momaka!
                          I don't know how to explain by words how great your answers are.

                          I can only say THANK YOU VERY MUCH @momaka for this level of the knowledge that you just shared in here!

                          Comment


                            #14
                            Re: [help required] which capacitor type for monitor power board

                            I finally got the capacitors that I bought from digikey. I decided to test them with DER DE-5000 ESR meter and compare results with their data sheets.

                            Most capacitors had much better stats then what is written in data sheets. For instance small nichicon ones, had 2.5 ESR in datasheet, and only 0.5 ESR when measured. Which is way better!

                            I only have doubs about one capacitor series. I order 5pcs of that capacitor and I measured them all, and they are all almost the same, but worst then what it was stated in their datasheets.

                            It's about Panasonic FR 1000uF/35V capacitors.

                            First I have to say that I calibrated ESR meter before I measured anythng.


                            Panasonic FR series datasheet for 1000uF/35V states:

                            Capacity (Ofcorse) = 1000uF
                            Impedance (@ 100 kHz, 20C) = 0.018 Ohm




                            Problem is, ..while I also bought FR series capacitor for 1000uf/25v (25 volts), I measured that one at above 1000uF.

                            But this one, 1000/35 it measures (@ 120 Hz) 895uF. I tested all 5 pcs of the same capacitor and they are almost equal in measured values. (I know its still 'in 20% +- specification but why its below while other cap form FR series 1000/25 is above 1000uF). I've also checked the vent and the bung, and they match Panasonic one (I mean, they are bought from DigiKey afterall)



                            As you see from the photo above I measured capacity at 120 Hz as per datasheet. Room temperature was maybe not 20, but up to 22C degrees. (so it can't make that much difference).


                            I then checked ESR by switching ESR meter to measure at 100 kHz, and I also got bad results compared to datasheet. While measuring all other caps that I bought (rubycon, nichicon and other panasonic) I got much better results.

                            This one (FR 1000/35) should have ESR of 0.018 (or better) but in reality it has 0.030. (all 5 pcs of the same capacitor, had the same 'high' ESR value).

                            Here check the picture:



                            ^thats the best result I got, but the rest of the caps (other 4 pcs) measured ESR as 0.030



                            The only 'positive' thing is that datasheet states that 'tangas delta' for 35v caps shoudl be 0.12 while I measured (check 2nd picture) 0.037.




                            So...my question is... are these caps good?

                            To make things even worse, all the other caps that I got, I bought with the idea to change all the caps on my monitor power board, but actuall cap that leaked is that one 1000uF/35v. Of all the caps, just the one that created this whole mess with my monitor power board, it happens that just that one that I bought to 'fix the issue' makes me suspicious about it (all 5 pcs of it).
                            Attached Files
                            Last edited by twist3r; 11-11-2017, 06:59 PM.

                            Comment


                              #15
                              Re: [help required] which capacitor type for monitor power board

                              Originally posted by twist3r View Post
                              So...my question is... are these caps good?
                              Yup, they should be fine.

                              I've had many new capacitors read with lower capacitance than stated (but still within 20%). Practically, my entire stock of Nichicon HM (or was it Rubycon ZLH, I can't remember) 10V, 1000 uF caps read closer to what you would expect for a 820 uF cap. But I've used a ton of them, and it's never been an issue. Most PSU high-voltage caps (as in 100V and higher) will also report lower capacity.

                              As for the higher ESR - that might be due to the low test voltage of your LCR meter. Again, I do recall seeing a few caps come that way. Nonetheless, I used those as well. Haven't had a recap repair come back yet.

                              Comment


                                #16
                                Re: [help required] which capacitor type for monitor power board

                                Thanks again momaka for your fast respond!

                                Comment


                                  #17
                                  Re: [help required] which capacitor type for monitor power board

                                  I agree with momaka.
                                  I would try one thing though: send the pics and explanation to DigiKey.
                                  Maybe they will send you some new caps, worth a shot.
                                  Of course install the ones you have, I'm quite sure they are just fine
                                  "The one who says it cannot be done should never interrupt the one who is doing it."

                                  Comment


                                    #18
                                    Re: [help required] which capacitor type for monitor power board

                                    ESR and impedance spec.
                                    https://ec.kemet.com/case-missing-es...specifications
                                    Never stop learning
                                    Basic LCD TV and Monitor troubleshooting guides.
                                    http://www.badcaps.net/forum/showthr...956#post305956

                                    Voltage Regulator (LDO) testing:
                                    http://www.badcaps.net/forum/showthr...999#post300999

                                    Inverter testing using old CFL:
                                    http://www.badcaps.net/forum/showthr...er+testing+cfl

                                    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                    http://s807.photobucket.com/user/budm/library/

                                    TV Factory reset codes listing:
                                    http://www.badcaps.net/forum/showthread.php?t=24809

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