Combine 12V rail on DPS 750CB-A

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  • Prongs
    PSU and Caps Lo
    • Feb 2017
    • 7
    • Indonesia
    #1

    Combine 12V rail on DPS 750CB-A

    Hi. Found this PSU from HP XW9300. Along with its case. I plan to put my 6700k and GA-Z170X-Designare into it's case.. and swap 12V-C rail pin to 12V-CPU_0 and 12V-CPU_1. 12V-C 12.5A would be CPU rail, and 12V-CPU_0 and 12V-CPU_1 12.6A as 6+2 pin x 2 repectedly. Hopes it's enough to power my Windforce R9 290.

    This is the specs of said PSU


    As you can see 12VCPU-0 and 12VCPU-1 got 25.2Amp Combined while 12V-C got only 12.5Amp.

    My question is how can I Draw more amp onto 12V-C without trip OCP in said FakeRail.. (I called it Fake Rail because it is not quitely Seperate rail lol) I need 20Amp minimum the more the better (Damn those single 6 pin power VGA)

    Total combined power of 12V is 55 amp. Wich is quite Impresive for old PSU.



    The source of 12V Is the one that has 8 parallel solder joint near R155, R158, R159.

    12v-C is besides R945

    12vCPU-1 is below R157

    12vCPU-0 is the one that has C162 and R156

    Any pointer will help. Thank you.
    Tags: None
    • Stefan Payne
      Badcaps Legend
      • Dec 2009
      • 1267
      • Germany
      #2
      Re: Combine 12V rail on DPS 750CB-A

      Take a look at Datasheets of some Protection ICs.
      There are some Resistors you need to change - but not the Shunt Resistors. That's also the worst thing to do, due to the enormous heat capacity of the PCB in that area - you want to avoid soldering in that area at all cost!

        Comment

        • Prongs
          PSU and Caps Lo
          • Feb 2017
          • 7
          • Indonesia
          #3
          Re: Combine 12V rail on DPS 750CB-A

          I plan to make heatsink for resistor that below R159. Is that help? And wich resistor that I need to change?

            Comment

            • Behemot
              Badcaps Legend
              • Dec 2009
              • 4845
              • CZ
              #4
              Re: Combine 12V rail on DPS 750CB-A

              Arent those joints of current shunts?
              Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts

              Exclusive caps, meters and more!
              Hardware Insights - power supply reviews and more!

                Comment

                • Prongs
                  PSU and Caps Lo
                  • Feb 2017
                  • 7
                  • Indonesia
                  #5
                  Re: Combine 12V rail on DPS 750CB-A

                  Originally posted by Behemot
                  Arent those joints of current shunts?
                  Yeah I believe... Those 4 joints

                    Comment

                    • Behemot
                      Badcaps Legend
                      • Dec 2009
                      • 4845
                      • CZ
                      #6
                      Re: Combine 12V rail on DPS 750CB-A

                      I am still not sure, better take an image of the upper side as well.
                      Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts

                      Exclusive caps, meters and more!
                      Hardware Insights - power supply reviews and more!

                        Comment

                        • Prongs
                          PSU and Caps Lo
                          • Feb 2017
                          • 7
                          • Indonesia
                          #7
                          Re: Combine 12V rail on DPS 750CB-A

                          Originally posted by Behemot
                          I am still not sure, better take an image of the upper side as well.
                          Okay.. after I comeback to my workshop..

                            Comment

                            • Prongs
                              PSU and Caps Lo
                              • Feb 2017
                              • 7
                              • Indonesia
                              #8
                              Re: Combine 12V rail on DPS 750CB-A

                              This is upside section of said psu. The white cable is the ones that I want to combine. Each is 12.6 amps.
                              Attached Files
                              Last edited by Prongs; 03-05-2017, 03:45 AM.

                                Comment

                                • jazzie366
                                  Badcaps Veteran
                                  • May 2016
                                  • 304
                                  • United States
                                  #9
                                  Re: Combine 12V rail on DPS 750CB-A

                                  Originally posted by Prongs
                                  This is upside section of said psu. The white cable is the ones that I want to combine. Each is 12.6 amps.
                                  That, is one nice PSU.
                                  Popcorn.

                                    Comment

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