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Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

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    #1

    Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

    Hello Everyone!

    Well, I am new to this forum and am very grateful for the support so far (in reading other's posts and such).

    I am in the process of resurrecting a PowerMac G4 Sawtooth (Dual 550mhz) that had been completely stripped and was being thrown out because of 'problems'. Being the packrat, I was able to scrounge things I need (except for a CD/Zip caddy - got one anyone? ) to get it operational.

    Upon first inspection, I found that the PS fan was *completely* dead. I could barely turn it with my fingers!!

    See 1st Fig - the Troubled Children. As a matter of fact, *both* fans in this Sawtooth were bad - the 120mm case fan did at least turn, but very, very noisily.

    Anyway, I pulled the PS, a Delta DPS-338BB A Rev:01 (Fig 2) so that I could replace the PS Fan:

    While I had it open, I noticed that one of the capacitors was starting to bulge. Thanks to Badcaps.net, I knew that this was a bad sign.
    Fig. 3, Fig. 4 (just to the right of the words, 'Bad Cap')

    As an aside, is the browning of the PCB a bad thing too? (See Fig. 5)

    Keep in mind, I have no idea how long this was operating without a functioning PS fan before they decided to trash it.

    Moving on, I pulled out my trusty soldering iron/removal bulb and pulled the bad capacitor. (See Fig. 6,7,8,9,10 - maybe overkill in pics, but I wanted to be sure you knew exactly what I pulled).

    So, here I stand with a PS missing a capacitor (all the other's looked fine) and wondering...where can I get a replacement???

    I did some researching online and my understanding is that as long as the capacitance matches, I can put one in that has an equal to or higher voltage rating.

    I came across some posts suggesting I replace with Nichicon 1000uF 25V Part #: UVX1E102MHA but apparently those have been discontinued in favour of UVR1E102MPD.

    However, I'm at TTI's website (www.ttiinc.com) and their minimum order is 200 capacitors!!!!

    I only need one......

    So, does anyone, perhaps have any suggestions as to where I could pick up one capacitor? I checked radioshack, and they have some 1000uF axial-lead electrolytic capacitors (1000uF, 35V). Should I get one of these, or is there a better/cheaper way to get one?

    I would appreciate any suggestions,thoughts, or concerns regarding this project. 8-)

    Thanks, Ran
    Attached Files
    ---
    Integrity - doing the right thing even when no one is looking

    Freedom - not the right to do as you please, but the liberty to do as you ought.
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    #2
    Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

    This capacitor (Teapo SEK Series) is not a low-ESR unit, and I would not guarantee them for use in switching power supplies. I only recommend using low-ESR units (my new favourite is the Nippon Chemi-Con KY Series) in such a supply.
    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

      #3
      Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

      Originally posted by japlytic
      This capacitor (Teapo SEK Series) is not a low-ESR unit, and I would not guarantee them for use in switching power supplies. I only recommend using low-ESR units (my new favourite is the Nippon Chemi-Con KY Series) in such a supply.
      First, thanks for responding. Umm...I'm confused. If these capacitors are 'not recommended' for switching power supplies...then..well...*why* is it in one?

      Secondly, where do hobbyists go to purchase just a few capacitors at a time online with minimal shipping charges? I found links to Mouser.com and Digikey.com...but their shipping costs are about 10x the cost of the capacitor!

      I looked at radioshack.com, and, while their costs are much higher, factoring in the shipping costs of those two online companies actually makes RadioShack an overall cheaper bet. I found this one:RadioShack 1000uF/35v, but I have no idea of the quality...

      Thirdly, If I detect no visual damage to the other capacitors, then it's fine if I leave them, right? I mean, my time is money....and while removing/replacing one capacitor is no big deal, I really don't want to sit here and remove *all* of them....

      Ran
      Last edited by ran; 10-18-2006, 06:59 AM.
      ---
      Integrity - doing the right thing even when no one is looking

      Freedom - not the right to do as you please, but the liberty to do as you ought.

      Comment

        #4
        Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

        If you value your time realy, stay away from those mdiocre generall purpose caps and do replace all the larger caps with 105°c rated and well branded ones..
        You would certainely spend more time and more money, if you do it not right at the very first attempt.
        Even if the other caps do not have signs of failure, they are certainely degraded if used w/o cooling. Thus you can decide to remove them now or later.

        I highly recomend Panasonic FC or FM ones, wich are easily availiable from Topcat or RS-online, Farnell and Digi-key.
        I think there is anything clearely stated, the choice is yours.

        Comment

          #5
          Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

          Hrrrmm..well, I was hoping that just replacing *one* of the capacitors would be sufficient..but I guess I can see the logic/wisdom in replacing more.....

          So, If I just replace the larger ones..let's see..that would be about 8 capacitors.

          *sigh*

          OK, for someone in the U.S., is Mouser.com the best place to go (despite shipping prices) or is there somewhere else?

          Is 'NiChicon" just short for NIppon CHemi-CON?

          For Panasonic's, in the US, where's the best place(reasonable shipping rates?)

          Again, thanks for the help, guys.

          Ran
          ---
          Integrity - doing the right thing even when no one is looking

          Freedom - not the right to do as you please, but the liberty to do as you ought.

          Comment

            #6
            Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

            Originally posted by ran
            Is 'NiChicon" just short for NIppon CHemi-CON?
            No, it's different brand.

            Comment

              #7
              Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

              Originally posted by Rainbow
              No, it's different brand.
              OK. good to know. So, it seems there are three recommendations, NiChiCon, Nippon, and Panasonic (all low-ESR).

              According to the FAQ - Mouser, Digikey, and Newark are really the only majour source of caps' online that will sell in relatively small quantities....

              Checking Newark, they have, "United Chemi-Con" (is this Nippon?), Illinois capacitor, Multicomp, and CDE Mallory (for 1000uF, 25V radial, ROHS compliant).....

              So, how do I know *which* one of these to choose? I have no idea what "series" or "tolerance" I need.....

              Thanks, all!
              Ran
              Last edited by ran; 10-18-2006, 11:18 AM.
              ---
              Integrity - doing the right thing even when no one is looking

              Freedom - not the right to do as you please, but the liberty to do as you ought.

              Comment

                #8
                Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                DO NOT buy that GP cap in the Radio Shack link! Beside being an 85C GP part, it is axial lead, when you need radial lead (both leads from the bottom of the part). Look for: Nichicon PM (lead-free version of PL), PS (lead-free version of PR), PW, or HE (the latter two preferred over the former); Panasonic FC or FM; UCC/NCC (United/Nippon Chemi-Con) LXV, LXY, LXZ, KY, or KZE. Rubycon has several good series - YXG, YXH, ZL - but their availability is poor in the US (I think that's where you are). CDE, IIRC, concentrates on larger sized parts. Illinois Capacitor is a second tier company, but might be OK if the application doesn't require really low impedance.

                Maybe my memory is slipping, but didn't Sawtooth hit the market in the late 90s, early 00s, possibly with G3 processors? It sounds familiar, but I don't recall a P/S (I worked at Delta, and supported Apple on a couple of projects) with a +28V Standby O/P and no +5V Standby O/P. Maybe this was the generation previous to Sawtooth, "Yosemite"?
                Last edited by PeteS in CA; 10-18-2006, 01:54 PM.
                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

                  #9
                  Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                  Originally posted by PeteS in CA
                  DO NOT buy that GP cap in the Radio Shack link! Beside being an 85C GP part, it is axial lead, when you need radial lead (both leads from the bottom of the part). Look for: Nichicon PM (lead-free version of PL), PS (lead-free version of PR), PW, or HE (the latter two preferred over the former); Panasonic FC or FM; UCC/NCC (United/Nippon Chemi-Con) LXV, LXY, LXZ, KY, or KZE. Rubycon has several good series - YXG, YXH, ZL - but their availability is poor in the US (I think that's where you are). CDE, IIRC, concentrates on larger sized parts. Illinois Capacitor is a second tier company, but might be OK if the application doesn't require really low impedance.

                  Maybe my memory is slipping, but didn't Sawtooth hit the market in the late 90s, early 00s, possibly with G3 processors? It sounds familiar, but I don't recall a P/S (I worked at Delta, and supported Apple on a couple of projects) with a +28V Standby O/P and no +5V Standby O/P. Maybe this was the generation previous to Sawtooth, "Yosemite"?
                  Ahh...good catch on the radio shack one - I gave the wrong link, it's really this one: RadioShack Radial 1000uF 35V

                  How do I find out what RadioShack's supplier is, I wonder.........

                  Regarding the Powermac model, it's not a Yosemite (no Gigabit ethernet) and this is definitely a dual 550mhz Gigabit, so, it's a Sawtooth. I actually wound up booting it anyway with the bad cap just to see if the thing would post..and..it does! So I promptly shut it down and took out the PS to do the Cap replacements.....

                  Thanks for the info on what series to get. Are all those 'Low ESR'? I find many at Mouser and Digikey that list caps with those initial letter designations and 105oC temp rating, but they don't specifically state 'low ESR'...

                  Again, thanks,
                  Ran
                  ---
                  Integrity - doing the right thing even when no one is looking

                  Freedom - not the right to do as you please, but the liberty to do as you ought.

                  Comment

                    #10
                    Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                    The series I listed are all low impedance (low ESR) series and, with the possible exception of the PR/PS series, are fairly commonly available. Radio Shack probably doesn't show its vendors in website pics so they can buy from multiple sources.
                    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

                      #11
                      Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                      I recommend that you not spend the time on this PSU, because after a fan has failed and it ran like that, all the parts have baked at high temp and may have shortened lifespans as a result (if not worse).

                      It is fair to think there was nothing wrong with the cap they used, only that the fans died then baked everything (more than just caps, they're just the things most visibly effected sometimes).
                      Last edited by 999999999; 10-19-2006, 12:03 AM.

                      Comment

                        #12
                        Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                        Other components are not that sensitive to heat. And it works so it's probably not in very bad shape.

                        Comment

                          #13
                          Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                          Actually yes the other components ARE sensitive to heat, when you're talking about the levels of heat possible from having no fans running at all, in a PSU designed to be actively cooled. However, we don't know how long it ran like that, it may well have shut itself off after overheating past a certain trip point.

                          Comment

                            #14
                            Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                            i would recap completely and put it back to work(with new fans too)

                            Comment

                              #15
                              Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                              Originally posted by kc8adu
                              i would recap completely and put it back to work(with new fans too)
                              Thanks for the suggestions, everyone. I have pulled out 12 of the 14 caps - two of the littlle ones are very hard to get to and are glued with that white stuff to other things, so, unless someone thinks it's a 'really bad thing'(tm), I'm going to leave them...

                              Finally, there are two *really* BIG cap's on here - I've attached pics, but they are rated at 200V, 820uF. Is there any reason to replace these big things as well if they "look" fine?

                              I can't thank y'all enough for the help...I am excited with this project and can't wait to see how it turns out (hopefully without a lot of heat, light, and smoke!)

                              Ran
                              Attached Files
                              ---
                              Integrity - doing the right thing even when no one is looking

                              Freedom - not the right to do as you please, but the liberty to do as you ought.

                              Comment

                                #16
                                Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                                Ah, the main PCB was fab'ed in August of 2000.
                                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

                                  #17
                                  Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                                  Originally posted by ran
                                  Hrrrmm..well, I was hoping that just replacing *one* of the capacitors would be sufficient..
                                  About two years ago, my 300W Antec that was then probably two years old, developed a swollen Fuhjyyu cap on ths +12V output rail. All the other caps looked OK and showed low ESR, so I left them along. But two weeks later, the other cap on the +12V rail sweled and showed 10x the ESR it had previously. So now I replace all caps of a given brand and type even if only one has gone bad.

                                  Comment

                                    #18
                                    Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                                    Originally posted by larrymoencurly
                                    About two years ago, my 300W Antec that was then probably two years old, developed a swollen Fuhjyyu cap on ths +12V output rail. All the other caps looked OK and showed low ESR, so I left them along. But two weeks later, the other cap on the +12V rail sweled and showed 10x the ESR it had previously. So now I replace all caps of a given brand and type even if only one has gone bad.
                                    ok - so, just that particular brand/type. Hence, I shouldn't have to replace those two very large cap's (200V/820uF) ones, correct?
                                    ---
                                    Integrity - doing the right thing even when no one is looking

                                    Freedom - not the right to do as you please, but the liberty to do as you ought.

                                    Comment

                                      #19
                                      Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                                      It seems that those high voltage caps fail a lot less because they work at 120 Hz rather than the high frequences that the low voltage caps do.

                                      Comment

                                        #20
                                        Re: Help with replacing caps in a G4 Sawtooth PS (Delta DPS-338BB)

                                        Originally posted by larrymoencurly
                                        It seems that those high voltage caps fail a lot less because they work at 120 Hz rather than the high frequences that the low voltage caps do.

                                        Good to know!

                                        I've ordered all my Cap's from Mouser.com....

                                        Here's hoping the recapping goes well....

                                        ARe there any recommended procedures for "testing" a PSU assuming I just have my multimeter... (I can test the 3.3,5, and 12v rails ...but what else?)

                                        Ran
                                        ---
                                        Integrity - doing the right thing even when no one is looking

                                        Freedom - not the right to do as you please, but the liberty to do as you ought.

                                        Comment

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