Announcement

Collapse
No announcement yet.

Asus Prime Z270-P no Vcore

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Asus Prime Z270-P no Vcore

    Hi guys

    I have an Asus Prime Z270-P.

    With no CPU fitted it will not start

    With a Celeron G3900 CPU it starts but the CPU is cold and I have no Vcore

    12V to the 8 pin molex is good, as are 12V, 5V, 3.3V to the ATX connector

    Checking with a scope I have no drive to the high side gate of the Vcore MOSFETs, the gate is 0V. I didn't bother check the low side.

    The MOSFET are M3054M

    There is this chip uP1540P near the MOSFETs. Each high side FET has one pin of an 820R resistor connected to the gate and some of theee resistors then connect to one pin on the uP1540P but not all of them. The ones that do all connect to the same pin on uP1540P. I can't find a datasheet for uP1540P.

    Also there is this other nearby QFN ASP1400BT that I think is the controller for the Vcore PSU, there look like 7 phases. But I can't find a datasheet for that either.

    I do have a 1.2V supply near the DIMM slots which is probably Vram and that is running OK.

    Looking for a board view plus datasheets for uP1540P and ASP1400BT plus any helpful advice on diagnosing the fault

    It looks like there is a board view on a paysite which also has the MS6178 schematics I need for another repair so I may have to pay there

    Cheers
    Rich
    Attached Files
    Last edited by dicky96; 03-25-2020, 08:32 AM.
    Follow me on YouTube
    ------------------
    Learn Electronics Repair
    https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

    #2
    Re: Asus Prime Z270-P no Vcore

    That would more likely be something like 4 Vcore + 2 VCCGFX + 1 VCCSA. Check if you get something on any of the inductor as VCCSA has to come up before the others. There should also be a VCCIO that comes up before VCCSA.
    No damage inside CPU socket? CPU VCore not shorted to ground?
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment


      #3
      Re: Asus Prime Z270-P no Vcore

      i found a pinout for the uP1540P https://www.chinafix.com/forum.php?m...m=album&page=1
      All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

      Comment


        #4
        Re: Asus Prime Z270-P no Vcore

        Hi guys
        I don't think that pinout is the same as my device as it only has 10 legs unless there are some pads underneath it. It's a bit of an odd shaped package, I don't know that that is called.

        Anyway I have 12V on what I assume is pin 1 (nearest the dot) and 0V on all the other pins

        All of the 7 phase coils have 0V on them

        Rich
        Attached Files
        Follow me on YouTube
        ------------------
        Learn Electronics Repair
        https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

        Comment


          #5
          Re: Asus Prime Z270-P no Vcore

          How did that thumbs down icon get on this thread?? If I pressed a wrong button then ooops!
          Follow me on YouTube
          ------------------
          Learn Electronics Repair
          https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

          Comment


            #6
            Re: Asus Prime Z270-P no Vcore

            There's probably a center pad connected to ground.

            What's the voltage on the inductors near the PCH?
            And the ones near the RAM?
            OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

            Comment


              #7
              Re: Asus Prime Z270-P no Vcore

              Yes some centre ground pad = pins 11/12/13 there is because I now have the board view

              I don't have any Vcc to the uP1540P

              This should help
              Attached Files
              Last edited by dicky96; 03-26-2020, 12:25 PM. Reason: more info
              Follow me on YouTube
              ------------------
              Learn Electronics Repair
              https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

              Comment


                #8
                Re: Asus Prime Z270-P no Vcore

                OK I took some voltages on the Colis and a few Power FETs

                PL2001
                +5VSB DUAL 4.98V
                PVDDQ REGIN S 4.98V

                PL2011
                PVDDQ PHASE 20 1.212V
                VDDQ 1.212V

                PL2211
                P+2V5 SW 2.510V
                VPPDDR 2.510V

                PL3011
                P +1.0V A SW 20 1.032V
                P1.0V A 1.022V

                PL1000
                +12V CPU 12.18V
                P VCORE L +12V S 12.18V

                PL1010 / PL1020 / PL1030 / PL1040
                P VCORE PHASE 1/2/3/4 20 OV
                VCORE 0V

                PL1310 / PL1320
                P GT PHASE 1/2 20 0V
                VCC GT 0V

                PL1511
                PVCCSA PHASE 20 0V
                VCCSA 0V

                PU1511 (uP1540P)
                PIN1 PVCCSA BOOT 20 12.18V
                PIN5 PVCCSA VCC 20 12.18V
                All other pins 0V

                Now here is the interesting thing...

                uP1540 pin 8 is P VCCSA POK and its 0V. This comes from a resistor PR1063. The other end of PR1063 P VCORE EN 10 connects to pin 2 of PU1000 (ASP1400BT) and this is 2.027V.

                But this is because the resistor PR1063 is missing from my board and as this looks like it is the enable pin for uP1504P I don't see how it could work without it! Also the soldering here looks 'shiny' like maybe someone has been messing. The same with capacitor PC1509, which is missing, and which connects from pin 10 of uP1504P (P VCCSA REFOUT 10) to ground - but I don't think that is quite so critical.

                The board view says this resistor is MBS_R0402 but a lot of the resistors say the same. I measured PR1596 in circuit which also says MBS_R0402 and that reads 256R

                What do think? I should put something like a 270R resistor in there and see what happens? And maybe a capacitor of some value in missing PC1509?
                Attached Files
                Follow me on YouTube
                ------------------
                Learn Electronics Repair
                https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                Comment


                  #9
                  Re: Asus Prime Z270-P no Vcore

                  Wrong pic

                  This one....
                  Attached Files
                  Follow me on YouTube
                  ------------------
                  Learn Electronics Repair
                  https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                  Comment


                    #10
                    Re: Asus Prime Z270-P no Vcore

                    It just occurred to me that MBS_R0402 will be the size of the SMD resistor, nothing to do with the value DOH

                    What value to put in there? I don't think it would be critical...
                    Follow me on YouTube
                    ------------------
                    Learn Electronics Repair
                    https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                    Comment


                      #11
                      Re: Asus Prime Z270-P no Vcore

                      That definitely looks to be no stuff.
                      Check voltage on VCCIO.
                      OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                      Comment


                        #12
                        Re: Asus Prime Z270-P no Vcore

                        Originally posted by piernov View Post
                        That definitely looks to be no stuff.
                        Check voltage on VCCIO.
                        Sorry didn't your reply, could you elaborate?
                        Follow me on YouTube
                        ------------------
                        Learn Electronics Repair
                        https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                        Comment


                          #13
                          Re: Asus Prime Z270-P no Vcore

                          Where is VCCIO I can't find that? Maybe it has another name on my board

                          There is 3.3V on some of the capacitors integrated onto the north bridge and 1.02V on the others. The north bridge gets warm but not hot

                          There are no shorts from any of the inductors to ground

                          rich
                          Follow me on YouTube
                          ------------------
                          Learn Electronics Repair
                          https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                          Comment


                            #14
                            Re: Asus Prime Z270-P no Vcore

                            YES!! I have a result!

                            I took a half educated guess and fitted a 470R resistor in place of missing PR1063. I didn't bother with what looks like a missing capacitor PC1509 partly because I don't think it is critical to have the capacitor but mostly because I have no 0402 SMD Caps!

                            And hey presto she fired up like a good 'un.

                            I attached a HDD with Windows 10 on it, booted windows and I'm online. I used SDI 1.20.0 to install all the drivers and everything looks rosy

                            Job done!
                            Follow me on YouTube
                            ------------------
                            Learn Electronics Repair
                            https://www.youtube.com/channel/UCFX...R8UZ2vg/videos

                            Comment


                              #15
                              Re: Asus Prime Z270-P no Vcore

                              Originally posted by dicky96 View Post
                              Yes some centre ground pad = pins 11/12/13 there is because I now have the board view

                              I don't have any Vcc to the uP1540P

                              This should help
                              Thanks bro

                              Comment

                              Working...
                              X