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    Replacing 4 diodes with a bridge

    I want to replace these Diodes with a GBU808 (I know overkill...) and I see where the positive side is but I'm not sure where the other pins of the rectifier would go, I know it's probably pretty simple, I just don't want to do it wrong
    Attached Files

    #2
    Re: Replacing 4 diodes with a bridge

    Why do you want to do that? I would think just leaving them the way they are. If you do blow one then you dont have to replace the whole bridge chip.

    Northpoint

    Comment


      #3
      Re: Replacing 4 diodes with a bridge

      Here you are P4

      Blue - AC
      Yellow - DC (marked + and -)
      Red - unused
      Attached Files
      Muh-soggy-knee

      Comment


        #4
        Re: Replacing 4 diodes with a bridge

        Thank you ben7!!! It's a Sun Pro...I already added an X cap, replaced the 220uF input caps with 470uF, and replaced the fake Y caps with real ones, so the input will be in good shape

        Comment


          #5
          Re: Replacing 4 diodes with a bridge

          Originally posted by Pentium4 View Post
          Thank you ben7!!! It's a Sun Pro...I already added an X cap, replaced the 220uF input caps with 470uF, and replaced the fake Y caps with real ones, so the input will be in good shape
          Mind if you could get us a pic or two of the final job (when the bridge-rectifier arrives)?
          Muh-soggy-knee

          Comment


            #6
            Re: Replacing 4 diodes with a bridge

            Yeah! Here is the before and after, and a pic of a typical Chinese cap lying about the specs! I think maybe some of the little caps on the 5VSB are bad because this thing has no signs of life. I will work on it more on the 31st and hopefully get it going
            Attached Files

            Comment


              #7
              Re: Replacing 4 diodes with a bridge

              Man that capacitance/ESR gadget is exactly what I'm looking for ! Where can I get one of these? How much does it cost?

              Comment


                #8
                Re: Replacing 4 diodes with a bridge

                Isn't it awesome? I saw tom66 had the ESR60 so I bought the newer version. I found one on ebay, it's ~$128 (97€) shipped but worth it!

                Comment


                  #9
                  Re: Replacing 4 diodes with a bridge

                  http://www.ebay.co.uk/itm/NEW-Peak-A...item519f47c5a1

                  Comment


                    #10
                    Re: Replacing 4 diodes with a bridge

                    Thanks!

                    Comment


                      #11
                      Re: Replacing 4 diodes with a bridge

                      I elected to get the ESR60 because I didn't think the audible alerts would be useful (it's £20 extra), but do you find them useful?
                      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


                        #12
                        Re: Replacing 4 diodes with a bridge

                        Originally posted by Pentium4 View Post
                        Yeah! Here is the before and after, and a pic of a typical Chinese cap lying about the specs! I think maybe some of the little caps on the 5VSB are bad because this thing has no signs of life. I will work on it more on the 31st and hopefully get it going
                        Thats not good!

                        Was it working before you did the mods to it?
                        Muh-soggy-knee

                        Comment


                          #13
                          Re: Replacing 4 diodes with a bridge

                          Originally posted by tom66 View Post
                          I elected to get the ESR60 because I didn't think the audible alerts would be useful (it's £20 extra), but do you find them useful?
                          It can be useful, plus it detects ESR up to 40 ohms compared to 20. I saw one (only slightly bulging CapXon) hit 26.6 ESR!!!!
                          Originally posted by ben7 View Post
                          Thats not good!

                          Was it working before you did the mods to it?
                          No it wasn't working before. But the start up cap is a Ricon so it's probably toast and needs to be replaced
                          Last edited by Pentium4; 12-29-2012, 01:18 PM.

                          Comment


                            #14
                            Re: Replacing 4 diodes with a bridge

                            Originally posted by Pentium4 View Post
                            No it wasn't working before. But the start up cap is a Ricon so it's probably toast and needs to be replaced
                            Oh no wonder ... a noname capacitor.

                            It looks like this has a two-transistor 5vsb, so if you don't get it fixed with new caps, then you could do the smps chip mod. (Like the VIPer22 or DM311)
                            Muh-soggy-knee

                            Comment


                              #15
                              Re: Replacing 4 diodes with a bridge

                              Yeah hope it works! But if it comes to that then I should give it a shot Some cap names make me laugh....one of the caps is "Sapcon"

                              Comment


                                #16
                                Re: Replacing 4 diodes with a bridge

                                Originally posted by Pentium4 View Post
                                Yeah hope it works! But if it comes to that then I should give it a shot Some cap names make me laugh....one of the caps is "Sapcon"
                                I'll never forget the 'Scatronics' brand capacitor I found in a el-cheapo computer speaker
                                Muh-soggy-knee

                                Comment


                                  #17
                                  Re: Replacing 4 diodes with a bridge

                                  I'm slightly ashamed to ask , but what do you think of this ?:



                                  http://www.ebay.co.uk/itm/NEW-TRANSI...item25791913e6

                                  Comment


                                    #18
                                    Re: Replacing 4 diodes with a bridge

                                    Not sure what your plans for that PSU are Pentium4, but it appears to be very similar (although slightly cheaper judging from the heatsinks) to this one I rebuilt a while back if you want some ideas.
                                    https://www.badcaps.net/forum/showth...hlight=gutless

                                    link directly to the rebuild post:https://www.badcaps.net/forum/showpo...93&postcount=8

                                    Comment


                                      #19
                                      Re: Replacing 4 diodes with a bridge

                                      Originally posted by TELVM View Post
                                      I'm slightly ashamed to ask , but what do you think of this ?:



                                      http://www.ebay.co.uk/itm/NEW-TRANSI...item25791913e6
                                      If I got that, first thing I'd do is get some socket-strips and solder then on.
                                      Attached Files

                                      Comment


                                        #20
                                        Re: Replacing 4 diodes with a bridge



                                        This is pretty good resolution for such an inexpensive device, no?
                                        "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

                                        -Leonid Brezhnev (On the Yom Kippur War)

                                        Comment

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