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GeForce GTX 1060 short on PCIe 12V

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    GeForce GTX 1060 short on PCIe 12V

    Hi everyone,

    I've been trying to find the cause for a short on 12v (~20 Ohms to
    ground) on a GTX 1060 for a while now, The card has no branding but
    as far as I can tell it is a Palit model. The short only shows
    up on the PCIe-connector but not the PSU connector.

    Initially I suspected a faulty MOSFET in the memory power supply.
    However after removing most of the MOSFETS/integrated power stages
    from the board: Q16 (SM4377 CS70X), Q17, Q18 (4503NH CS740), U10,
    U12, U14 (SIC632) and the PWM controller (NCP81174) the
    short is still there. As a last resort I decided to inject .7 V into
    the 12V rail on SC87, hoping that a faulty component would heat up.
    Unfortunately the card only draws ~40mA, not enough to produce any
    significant heat.

    I already took a look around here on the forum to find some
    schematics, unfortunately the Palit GTX 1060 cards seem to differ
    a lot from many other GTX 1060 models and use a different naming
    scheme for the components on the PCB.

    Since I've run out of ideas on how to tackle the problem
    systematically I hope that someone here has some advice how I could
    proceed cleverly to find the faulty component(s), without resorting
    to randomly removing/replacing components until I get lucky.

    Disclaimer: I realize that probably more info is needed to help me
    with the problem. If you need any additional data/info/measurements
    to be taken let me know which data is missing and I'll gladly try to
    provide it.

    Cheers
    Traceless
    Attached Files

    #2
    Re: GeForce GTX 1060 short on PCIe 12V

    12v is usually caused by mosfets make sure again if you properly checked the mosfets. Check datasheet and connect one probe of multimeter to gate of mosfet and other to ground on gpu.

    Comment


      #3
      Re: GeForce GTX 1060 short on PCIe 12V

      Hello ahmad9794,

      thanks for the response. That was my first thought as well. As you can see on the first two pictures I have already removed all MOSFETs responsible for supplying GPU and memory from the board, unfortunately the short is still present.

      Since the board only draws ~40mA I suspect that some smaller component maybe a capacitor, inductor or sth. like that went short. However so far I'm unable to locate the source of the problem.

      Comment


        #4
        Re: GeForce GTX 1060 short on PCIe 12V

        I would not think a 1060 would use 12v from the pci-e slot, on any large phase, as in the large ones around the main chip.

        I think 12v-mobo is used a lot for 5V to the video outputs, maybe the fan, maybe for some aux rails

        I'd look at the similar schematics if I knew where they were

        Start at the 6pin connector, and see what big caps are connected to it, and the upstream side of the big power mosfets. Do the same for the mobo connectors.

        That's what I would do anyways. I just fixed another power issue I caused on my GPU, but now I'm back to no video, but all the main voltages are running.
        Last edited by MasterCap; 08-09-2022, 10:22 PM.

        Comment


          #5
          Re: GeForce GTX 1060 short on PCIe 12V

          Today I finally found some time to take a look at the board again.

          Originally posted by MasterCap View Post
          I would not think a 1060 would use 12v from the pci-e slot, on any large phase, as in the large ones around the main chip.
          Thanks for the hints MasterCap. I assume the card might use PCIe 12V for the memory. Without schematics there is no way to be sure though. I think Q16, 17, 18 may belong to the memory power supply whereas U10 ... U14 belong to the GPU supply (U11, 13 were unpopulated though, probably the same board is used for 1070s as well, which require the additional phases).

          Originally posted by MasterCap View Post
          I think 12v-mobo is used a lot for 5V to the video outputs, maybe the fan, maybe for some aux rails
          I checked the HDMI output there seems to be a short on TDMS CLK+ (see this video), note sure though if that has to do with the cause of the problems or if it is just a symptom.

          Originally posted by MasterCap View Post
          I'd look at the similar schematics if I knew where they were

          Start at the 6pin connector, and see what big caps are connected to it, and the upstream side of the big power mosfets. Do the same for the mobo connectors.

          That's what I would do anyways. I just fixed another power issue I caused on my GPU, but now I'm back to no video, but all the main voltages are running.
          Unfortunately I don't have schematics and there is funky stuff happening all over the board. I made a video showing some examples of these problems. Sorry for the bad image quality my camera is not the best, so here is some additional explanation of what I'm doing:

          First I test two caps and an IC. Both caps have low resistance to ground on both ends (~.25 Ohms on the actual ground and ~.65 Ohms on the other end).

          Next I measure a capacitor on the other end of the board (SC87 c.f. pictures from my first post to be able to see the component names). SC87 seems to be connected to PCIe 12V (I soldered a wire to it for voltage injection). Both the cap and the PCIe connector have < 20 Ohms resistance to ground.

          Next I measure C67/C60/C59 both measure also < 20 Ohms to ground as does the cap below U14 (above Q17). In contrast the according caps below U10 and U12 measure ~500 k Ohms so I guess no problem there.

          I do see a lot of problems but still have no clue what is going on exactly.

          Comment


            #6
            Re: GeForce GTX 1060 short on PCIe 12V

            I think I might have finally found two suspicious parts, SC532 and SU5 (see picture below). Using Diode mode I measure a drop of 0.000V between pins 2 and 4 of SU5 and both sides of SC532. Can anyone identify part SU5 on the picture below? SU5 is labeled "08=R3M".
            Attached Files

            Comment


              #7
              Re: GeForce GTX 1060 short on PCIe 12V

              Originally posted by Traceless View Post
              Can anyone identify part SU5 on the picture below? SU5 is labeled "08=R3M".
              I think I might have identified the part, I'm not 100% sure but I think it might be an RT9403EGV8

              Comment


                #8
                Re: GeForce GTX 1060 short on PCIe 12V

                Originally posted by Traceless View Post
                I think I might have identified the part, I'm not 100% sure but I think it might be an RT9403EGV8
                yes

                Comment


                  #9
                  Re: GeForce GTX 1060 short on PCIe 12V

                  20 ohms, 40mA?
                  you may try this: put pcb on expanded polistyrene surface, connect 0.8v on "short" (btw what is voltage drop at 40mA?) and leave this about half hour on peace. Then use a NTC 10k flat sensor (from some liion batt) connected to multimeter, and scan surface that have accumulated heat spot.

                  Comment


                    #10
                    Re: GeForce GTX 1060 short on PCIe 12V

                    Originally posted by harp View Post
                    20 ohms, 40mA?
                    you may try this: put pcb on expanded polistyrene surface, connect 0.8v on "short" (btw what is voltage drop at 40mA?) and leave this about half hour on peace. Then use a NTC 10k flat sensor (from some liion batt) connected to multimeter, and scan surface that have accumulated heat spot.
                    Thanks for the tipp with the NTC, harp. Unfortunately the current draw was just to low to get any conclusive hints based on temperature and the card ended up in my drawer for quite some time. Yesterday I found some time to look at it again and finally found the fault. A ceramic capacitor (SC532) caused the short. I removed it and now 12V to ground resistance is back to 4.9kOhms, which seems healthy to me.

                    I also took of another ceramic capacitor next to C113, which has a thin black line on top, could be a surface scratch or a fissure. Either way I'd like to replace it just to be sure. It doesn't read short but I'm not sure if its capacitance (10 nF) is correct.

                    Also during voltage injection I accidentally damaged SC87. I soldered a wire to it and put some pressure on the board while it was lying flat on that wire - so one end broke of and I have to replace that one as well.

                    Since there seem to be no schematics for the board and the component numbering is very different from that used by other 1060 designs I was hoping someone could tell me the correct values for:

                    SC87
                    SC532
                    the missing SMD ceramic capacitor next to C113

                    I included pictures for reference.
                    Attached Files

                    Comment


                      #11
                      Re: GeForce GTX 1060 short on PCIe 12V

                      The manufacturer wish to lower cost as posible cost of his products, so it use only few common components on pcb. You may assume that other capacitor with same shape, size, and color be the same value, and if is at same arrangement or function it is even much possible that are the same.

                      The c532 is near a u5 chip... so find same size cap near other similar chip, desolder it and do measurement of them,
                      and c86 is in arrangement with near small cap, so find on pcb something simmilar... I think it is not critical value, if is on rail

                      Or you can trace capacitor function and value in datasheet of RT9403EGV8 if is contain schematic.
                      Last edited by harp; 12-28-2022, 02:32 PM.

                      Comment


                        #12
                        Re: GeForce GTX 1060 short on PCIe 12V

                        Thanks for the reply harp. According to the RT9403 datasheet could be 100 nF. Eyeballing the cap sizes is definitely plan B. If anyone knows the exact sizes or has schematics it would be great if they could post them here. If not I'll do it exactly the way you suggested.

                        Comment


                          #13
                          Re: GeForce GTX 1060 short on PCIe 12V

                          Meanwhile this 1060 is running again, however there is still a weird issue with the card that I haven't been able to figure out - The card dynamically switches between power states and boosts the RAM-clock however the GPU clock stays fixed at 139MHz regardless of the current power level. Some diagnostics I did:

                          - I measured the 3 GPU power phases with my oscilloscope. All are present and operational. Under load all three phases operate somewhere between 320 and 430 kHZ. When the card is idle the bottom phase stays at ~320kHZ while the top two go down to 30-50 kHZ.
                          - To rule out a driver issue I installed an older driver.
                          - I tested with two different 6-Pin power connectors and ensured that both carry 12V (PSU is a Corsair HX650W).

                          I took the screenshot below with nvtop while running the "Heaven" benchmark. You can see on that screenshot, that the card is detected as PCI gen 3 16x, the GPU load is at 100%, the power draw is only 31/120W so the card does not hit the power limit. Further the GPU is quite cool at 47°C. At the same time the memory clock ramps up to 3802 MHz which means the card is not running in "safe-mode".

                          At the moment I'm a bit at a loss - everything seems to be in order however the GPU stays at the minimum clock level. I'd be grateful if anybody had some clues how to further debug this problem.
                          Attached Files

                          Comment


                            #14
                            Re: GeForce GTX 1060 short on PCIe 12V

                            Power Sensor IC already checked ?

                            Comment

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