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    Are those two caps bad?

    Hi guys, I need some advice.

    Months ago, while my desktop PC was powered on, I heard a sudden "BANG" but paid no attention to it since the PC remained on.
    Since that day, a pop-up window appeared at every startup informing me that the graphics card could not receive sufficient power.
    I continued using that PC until one week ago, when I decided to open it up and check what was the problem with the card.

    I took it from its AGP slot and... tada! Found a broken capacitor, and FORTUNATELY nothing else appears burnt or damaged.
    I decided to try to repair the card by myself, but before buying any cap I decided to have a look at the PSU too.

    I found what you see in attachments: there're two huge caps with a strange, solid, brown "thing" at their bottom, but (forgive my ignorance) I can't decide if it's some sort of "glue" the designers put there for any purpose, or if it's the electrolyte the two caps had inside since the dawn of time!
    That brownish thing is only there on the PSU's PCB, not on other points where there's a glue which is obviously a glue.

    My questions are:

    1. do you think that those two caps are gone as well?
    2. should I try to replace them, or leave them where they're?
    -- in other words, would YOU replace them?
    3. the PSU is 12 years old, would you suggest me to replace only those caps, all other caps, or the entire PSU?
    4. how is it possible that, assuming those two caps are blown up, all peripherals were working good?
    -- (from the motherboard to the HDDs and DVD players)
    -- I don't know if it's relevant, but those two orange wires near the caps are connected to a voltage selector switch, 230V or 110V.
    5. should the caps be burnt, how to get rid of that brownish substance below them? Can I use simply some alcohol?
    6. can I eventually let it where it is, or it's conductive and/or corrosive and thus should be removed?

    I have no other questions for now
    Thanks for reading and, hopefully, for replying.
    Keep helping guys!, bye bye.
    Attached Files
    Theory is when nothing works but you know why. Practice is when things work but you don't know why.
    Theory and practice are combined when nothing works and you don't know why
    A. Einstein

    #2
    Re: Are those two caps bad?

    Glue. Might be conductive, so try to scrape it off if you can. Not really a problem at that place though.
    Last edited by Jooo; 05-06-2015, 03:10 AM.

    Comment


      #3
      Re: Are those two caps bad?

      When that glue dries out, it can carbonize and become electrically conductive.
      My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

      Comment


        #4
        Re: Are those two caps bad?

        no need, just change the bloweb capcitors

        Comment


          #5
          Re: Are those two caps bad?

          That psu is 200-250W max judging from those 330uF primary caps. You may consider replacing it with something decent.

          How many power the system draws?

          Comment


            #6
            Re: Are those two caps bad?

            Thanks all for your replies.
            So if i got it, you're suggesting me just to remove that glue without replacing the two caps.

            @goodpsusearch: yeah, the PSU is a 280W model.
            It's supplying power to two hard disks, one DVD player and one DVD burner, the motherboard, the graphics card (either by the AGP slot, and by an indepentent power connector), a floppy reader (yeah, you read it right!), and two fans.
            Theory is when nothing works but you know why. Practice is when things work but you don't know why.
            Theory and practice are combined when nothing works and you don't know why
            A. Einstein

            Comment


              #7
              Re: Are those two caps bad?

              Those are lousy JunFu capacitors. Replace them as soon as you can with Rubycon caps or something along the lines of that, like Nippon Chemi-Con caps.
              Don't buy those $10 PSU "specials". They fail, and they have taken whole computers with them.

              My computer doubles as a space heater.

              Permanently Retired Systems:
              RIP Advantech UNO-3072LA (2008-2021) - Decommissioned and taken out of service permanently due to lack of software support for it. Not very likely to ever be recommissioned again.
              Asus Q550LF (Old main laptop, 2014-2022) - Decommissioned and stripped due to a myriad of problems, the main battery bloating being the final nail in the coffin.


              Kooky and Kool Systems
              - 1996 Power Macintosh 7200/120 + PC Compatibility Card - Under Restoration
              - 1993 Gateway 2000 80486DX/50 - Fully Operational/WIP
              - 2004 Athlon 64 Retro Gaming System - Indefinitely Parked
              - Main Workstation - Fully operational!

              sigpic

              Comment


                #8
                Re: Are those two caps bad?

                Originally posted by ResistEnt View Post
                Thanks all for your replies.
                So if i got it, you're suggesting me just to remove that glue without replacing the two caps.

                @goodpsusearch: yeah, the PSU is a 280W model.
                It's supplying power to two hard disks, one DVD player and one DVD burner, the motherboard, the graphics card (either by the AGP slot, and by an indepentent power connector), a floppy reader (yeah, you read it right!), and two fans.
                What is the CPU and the graphics card of the pc?

                Originally posted by TechGeek View Post
                Those are lousy JunFu capacitors. Replace them as soon as you can with Rubycon caps or something along the lines of that, like Nippon Chemi-Con caps.
                JunFu are fine in primary section of psu, especially a non Active PFC unit like that.

                Comment


                  #9
                  Re: Are those two caps bad?

                  Well all the stuff is 12yo, not only the PSU!

                  CPU is an AMD Athlon XP 2200+ not overclocked (it runs at 1800MHz).
                  Graphics card is an NVIDIA GeForce 7600GS, AGP 8x model.

                  Wow goodpsusearch...
                  I posted four badly-taken photos and you told me the power of the PSU and also answered to a forgotten question I asked myself years ago... it's an active-PFC or passive-PFC PSU? Cool!!
                  Theory is when nothing works but you know why. Practice is when things work but you don't know why.
                  Theory and practice are combined when nothing works and you don't know why
                  A. Einstein

                  Comment


                    #10
                    Re: Are those two caps bad?

                    I will be able to tell you more if you post some pictures of the rest of the psu including its label :-)

                    Comment


                      #11
                      Re: Are those two caps bad?

                      Guys, I've some news.

                      First, I've managed to remove that brown glue (see attachments).
                      To never have put my hands on jobs like this, I'm pretty satisfied about the result

                      goodpsusearch, I also attached some other photos about the PSU, including its labeling.

                      I inspected the PCB accurately from either the components side and the traces side, and found no components burnt, no leaks, and no weird odds, just dust that I've blown away.

                      But actually there's one small capacitor with a little bulge on its top side.
                      The problems, besides the fact I never understood how to solder and my very few experiences with soldering, are:
                      • that capacitor is stuck to other caps with some white glue (ok, now I should be able to remove it lol)
                      • to desolder the capacitor, I'd have to remove the PCB from its case and this would imply to desolder the mains connector first :S


                      I don't know if I should attempt to replace that cap or not... I'm a bit afraid

                      Ah yeah I've also another question:
                      would you put some WD40 into the PSU fan to make it rotate more smoothly?
                      Ok maybe it's a dumb question for you ... but ...

                      Thanks a lot!
                      Bb.
                      Attached Files
                      Theory is when nothing works but you know why. Practice is when things work but you don't know why.
                      Theory and practice are combined when nothing works and you don't know why
                      A. Einstein

                      Comment


                        #12
                        Re: Are those two caps bad?

                        If you search the forum for "Premier", "Deer", "Allied" you will see that those psus are quite famous but for all the wrong reasons!

                        At least yours seems to have a full input filter for harmonics / EMI filtering from AC mains.

                        But, wait, what's this??

                        https://www.badcaps.net/forum/attach...1&d=1430998937

                        The 2 diodes on a bracket solution for 12V!! This is terrible!

                        You should seriously consider replacing this psu with something semi-decent.

                        The fact that your system is 5V based is the only reason the psu didn't burn already. If it was a Pentium 4 Prescott for example those 2 diodes wouldn't be able to provide the current needed to run the cpu and gpu.


                        WD40 is not suitable for fan lubrication. It is too thin and contains solvent that is not good for the plastics/rubber sheet. There is a thread about fan lubrication: https://www.badcaps.net/forum/showthread.php?t=2822

                        Personally I use Singer sewing machine oil
                        http://www.knitandsew.co.uk/images/SINGER-OIL-F.jpg
                        It is cheap and lasts forever, you only add some drops of it.

                        You could also use motor oil if you have some available.

                        You should also remove the glue from the caps because it keeps them in touch with the minimum load resistors and they get cooked eventually:
                        https://www.badcaps.net/forum/attach...1&d=1431000171
                        It's the same platform, but even more gutless than yours. The glue has been removed before I took the photo.
                        Attached Files

                        Comment


                          #13
                          Re: Are those two caps bad?

                          Originally posted by goodpsusearch View Post
                          What is the CPU and the graphics card of the pc?



                          JunFu are fine in primary section of psu, especially a non Active PFC unit like that.
                          Ummmm..... those are ticking time bombs. If one of those cooks, then most likely, a WHOLE lot more will fry than some caps.
                          Don't buy those $10 PSU "specials". They fail, and they have taken whole computers with them.

                          My computer doubles as a space heater.

                          Permanently Retired Systems:
                          RIP Advantech UNO-3072LA (2008-2021) - Decommissioned and taken out of service permanently due to lack of software support for it. Not very likely to ever be recommissioned again.
                          Asus Q550LF (Old main laptop, 2014-2022) - Decommissioned and stripped due to a myriad of problems, the main battery bloating being the final nail in the coffin.


                          Kooky and Kool Systems
                          - 1996 Power Macintosh 7200/120 + PC Compatibility Card - Under Restoration
                          - 1993 Gateway 2000 80486DX/50 - Fully Operational/WIP
                          - 2004 Athlon 64 Retro Gaming System - Indefinitely Parked
                          - Main Workstation - Fully operational!

                          sigpic

                          Comment


                            #14
                            Re: Are those two caps bad?

                            The primary caps are under a lot less load. If they fail, the power supply output ripple will increase considerably, but it shouldn't outright damage anything. They'd be among the last caps to fail.
                            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                            Comment


                              #15
                              Re: Are those two caps bad?

                              Yes, primary caps don't get stressed as much. They are more for holding up the main rail in between the mains cycles.

                              However, to be honest, I have no clue what would happen to the power supply if one or both went bad. I know it would make a lot of ripple on the output, but I don't know if it would mess with the circuitry enough to make the power supply go POP xD

                              Hm, ..... LOL!
                              I bet your cap on the graphics card was a Sacon FZ, was it not? People have those randomly go bang all the time!

                              These are Sacon FZ:


                              And yes, I say "No way José!" to the two-diodes-on-a-bracket thing in those cheapo PSUs.
                              Attached Files
                              Muh-soggy-knee

                              Comment


                                #16
                                Re: Are those two caps bad?

                                usually the primary caps failure leads to switching transistor / mosfet failing shorted or the psu cycling on and off intermittently if you are lucky.

                                Comment


                                  #17
                                  Re: Are those two caps bad?

                                  Originally posted by goodpsusearch View Post
                                  usually the primary caps failure leads to switching transistor / mosfet failing shorted or the psu cycling on and off intermittently if you are lucky.
                                  I wasn't sure if it would blow the switchers or not, but why would it do that? Excessive current pulses?
                                  Muh-soggy-knee

                                  Comment


                                    #18
                                    Re: Are those two caps bad?

                                    Thanks again for all your replies!

                                    Let's analyze some things.

                                    The PC that PSU is feeding is a 12yo PC as I already said.
                                    I've used it all the time since I bought it, it was definitely my "daily life PC": music, photos, surfing the Internet, and also playing 3D games. In short, it's been stressed very much, it's been switched on for many many hours (about 15 hours a day for the last two years) and, probby for the reason goodpsusearch stated above, the PSU has incredibly lasted.

                                    Ah yeah, at this point there also should be pointed out that the PSU has been directly connected to the line for only 4 years (2003-2007), since in 2007 I bought a UPS Winning move? Who knows...
                                    ( incidentally, as you may now guess, the question "does my PSU have an active- or passive-PFC circuitry?" came in my mind just then, when I was searching for a UPS )

                                    Anyway, this PC is no more my daily-life PC: I "dismissed" it two months ago and now I just want to re-put it in service for basic things, like surfing the web or playing old games sometimes, that is no important files would be saved inside and it wouldn't be a very big pain if it, some day, decided to get burnt...
                                    Of course, best thing would be it didn't, but again, no big pain if...
                                    I don't think it'll be switched on very often, either.

                                    So at this point I was thinking about removing the glue, lubricating the fun with motor oil (I've plenty of it), and maybe replace the only cap that's clearly going to death (it would be a nice soldering excercise introducing the REAL job, that is to replace the broken cap of the graphics card... and that will be the decisive challenge!).

                                    I don't think it's worth to replace the entire PSU, I mean it's lasted since now that there were important files inside the PC, now it can also crash if it wants to

                                    @ben7:
                                    of course, the failed cap on the GFX card is a Sacon crappy cap...
                                    It is searching for "FZ7C 1000 16V" that brought me here
                                    The card has just two Sacon caps (maybe, it should be spelled as "suck-on" lol), one dead and one still alive, and I was thinking about replacing both of them anyway. I have not checked the brand of all the other caps on the card, but they look visually different from the two Sacons, and appear to be ok.

                                    I'll have the weekend to better decide, 'cos I'm quite sure I won't be able to work on it till next Monday or Tuesday.

                                    Thanks again, bye.
                                    Theory is when nothing works but you know why. Practice is when things work but you don't know why.
                                    Theory and practice are combined when nothing works and you don't know why
                                    A. Einstein

                                    Comment


                                      #19
                                      Re: Are those two caps bad?

                                      Ah yeah ben7, by the way, I forgot to mention that the graphics card was the last upgrade I did to that PC.
                                      So it was the newer component, the only component which is not 12yo...
                                      Damn Sacon...
                                      Theory is when nothing works but you know why. Practice is when things work but you don't know why.
                                      Theory and practice are combined when nothing works and you don't know why
                                      A. Einstein

                                      Comment


                                        #20
                                        Re: Are those two caps bad?

                                        simple answer. it has no pfc at all!

                                        Comment

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