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    Elite 945GCT-M3 dead

    For several years I have been repairing computer power supplies, but now have decided trying to tackle repairing a motherboard. I have acquired a dead Elite 945GCT-M3 probably from emachine computer. Here is what I have found so far:

    The Power LED does not light up at all. I put a known good cpu and memory in the board. I installed a post tester in a pci slot. It reads FFFF indicating that the cpu is not doing anything. The LEDs on the post tester for 3.3v, 5v, 12v, and -12v all come on. The clk LED does not come on at all, so no clock signal. The RST LED stays on all the time. So looks like the reset line is hung up.

    Is the reset circuit part of the NorthBridge or SouthBridge chip? Where should I look for the reset circuit?

    If I can fix a Bestec ATX250-12E, then surely I can learn how to fix a motherboard!
    Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

    #2
    Re: Elite 945GCT-M3 dead

    Is this your motherboard?
    http://www.ecs.com.tw/ECSWebSite/Pro...uID=24&LanID=0

    Check if the CPU you are using is compatible with the motherboard. Also use only one stick of RAM (try both slots if motherboard doesn't POST)

    Next, check all of the pins in the LGA socket - even a single slightly mis-aligned pin can cause no POST.

    Make sure your CMOS battery is good. Some motherboards (very few, but they do exist) will not start without a CMOS battery. While at it, also remove the CMOS battery for about 20-30 seconds - this should reset all CMOS settings. Make sure the motherboard is disconnected from the PSU while doing this.

    If symptoms don't change, turn OFF and turn ON your motherboard, then keep hitting the Num Lock key on your keyboard. The Num Lock LED on the keyboard should come ON and OFF. If it gets stuck either ON or OFF while doing this, then something is making the motherboard lock up.

    After that point, it is time to measure the various voltage rails on the motherboard to see if they are present.
    Generally, that is:
    CPU V_core (1.2-1.4V, depending on CPU you have in there)
    RAM V_dimm (typically 1.8V for DDR2)
    RAM Vtt (termination voltage, typically half of V_dimm, or 0.9V)
    CPU Vtt (around 1.2V for most P4, PD, and C2D CPUs)
    Northbridge Vcc (around 1.4-1.5V for the Intel i9x5 series of chipsets)
    Southbrdige Vcc (varies by motherboard, but typically less than 2V)

    Here is a different ECS motherboard I posted about just yesterday, but if you look at the cap diagram, you may be able to see some similarities between yours and mine in terms of some of the voltage rails.
    https://www.badcaps.net/forum/showthread.php?t=63052

    Lastly, this being an ECS motherboard, it wouldn't be impossible that it has bad OST caps. Even if they all look good, chances are you may have a few that are bad. In particular, any OST RLZ and RLX caps should be suspect, as they fail most often. RLS series are a bit more reliable, but they can still dry out in hot areas. The ones around coils/inductors are most likely to have dried out.
    Last edited by momaka; 06-30-2017, 12:59 PM.

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      #3
      Re: Elite 945GCT-M3 dead

      Always nice to see the final results on a repair project, and this motherboard is no exception. Most boards can be fixed by replacing bad capacitors, so most of the capacitors on this board were replaced. Didn't help, same problem. Using a POST tester, I was able to determine that the reset line on the board was always staying high. I downloaded and studied the south bridge data sheet, 82801. All of the reset functions are located in this chip. So I spent more than a year looking for a company that could do south bridge BGA replacement. No company was willing to do this kind of work for an individual, but only for a commercial business. I now have access to a MetCal MRS-1100 rework station. I was able to remove the BGA southbridge chip. Using solder wick and no clean tacky flux (the type recommended for BGA rework) I was able to clean the motherboard in preparation for the replacement chip. Inspecting the board I was able to determine what the problem is.

      This board has numerous circuit traces broken where the BGA chip solders to the board. The picture shows three broken traces close together. Most likely, someone before me tried to remove and replace the southbridge BGA chip but did not have the right equipment for the job. The heat distribution for removing and replacing a BGA chip is critical. Circuit traces can be repaired (see www.circuitmedic.com). With so many traces to be repaired, I decided the board is not worth the effort. So this project came to a halt. As far as I am concerned, the board is not repairable.
      Attached Files
      Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

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        #4
        Re: Elite 945GCT-M3 dead

        Here is another broken trace. I made a picture with red circle to show the broken trace, and a picture without the red circle to get a closer perspective.
        Attached Files
        Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

        Comment


          #5
          Re: Elite 945GCT-M3 dead

          I counted twelve broken circuit traces. This shows a group of three. Some boards are simply beyond reasonable repair. So what do you think?
          Attached Files
          Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

          Comment


            #6
            Re: Elite 945GCT-M3 dead

            Ah yeah indeed this one is not in a good shape. The chip was pulled while some balls were not fully melted. When removing a dead chip, better overheat it that remove it when it's too cold.
            Desktop boards are not always easy to rework because they are fairly large, use fairly large BGA chips and have a high thermal mass. They are also heavy so they bend easily.

            Apparently the vias are still there so it may be repairable, but would be tedious.
            OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

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              #7
              Re: Elite 945GCT-M3 dead

              Originally posted by everell View Post
              Inspecting the board I was able to determine what the problem is.

              This board has numerous circuit traces broken where the BGA chip solders to the board. The picture shows three broken traces close together. Most likely, someone before me tried to remove and replace the southbridge BGA chip but did not have the right equipment for the job. The heat distribution for removing and replacing a BGA chip is critical.
              Not trying to undermine your troubleshooting experinece, but are you sure someone actually tried to replace the Southbridge before you? I find that very unlikely. If you still haven't cleaned the old solder balls from the Southbridge chip, check them out - if those ripped pads/traces are still attached to it, then that means your BGA chip wasn't hot enough when you removed it, as Piernov suggested. I myself have damaged a few test/experimental boards before like that when I was still learning BGA rework.

              That said, the MetCal MRS-1100 rework station you have is a really nice piece of equipment and should have been able to handle the task. But make sure you have it set correctly. A trick that I often use to check if a hot BGA chip is ready for removal is to give it a "nudge" with a toothpick on two opposite corners. If the BGA chip can move around easily, it's ready to be removed/pulled up.

              To make sure lack of heat/temperature/profile time is not your issue, perhaps continue practicing on this motherboard (i.e. try removing the NB, CPU socket, and etc.) Actually, salvaging the CPU socket could prove worthwhile if you have another LGA775 board that has too many mangled pins to fix (and if it's a "rare" or nice board.)

              By the way, I think I have a motherboard here that needs a Southbrdige replacement as well (SB overheats as soon as PC is powered On). I think the SB on my board was a 82801, but I would have to check. If it is, would you like another project board? Or if not and you don't need the removed 82801, perhaps I'll send you a PM to buy it off. Also have another board (a Fic AM37 from an e-Machines PC) that needs a LPC SIO (ITE IT8705F) - killed by one of your favorite repair PSUs: the Bestec ATX-250-12E.
              Last edited by momaka; 03-21-2019, 05:48 PM.

              Comment


                #8
                Re: Elite 945GCT-M3 dead

                Indeed this was my first attempt at southbridge BGA replacement. I experimented with a lot of temperature profiles before starting. I removed the BGA chip on three practice boards before attemping the replacement on this one. All three came of nicely without damaging the board, and cleaned nicely using solder wick and special flux for BGA chips.

                After removing the BGA chip from this board, it looked much different. There were large globs of solder on the PC board, very different from the previous three boards. After cleaning the board, I found numerous circuit traces damaged. Also several large areas of solder mask had been burned off. Since the original problem was the reset line staying high, the problem was probably caused by a bad connection (or broken trace) between motherboard and BGA chip. This is why I thought someone ahead of me had attempted BGA replacement. I don't think the MetCal machine would have done this much damage.
                Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

                Comment


                  #9
                  Re: Elite 945GCT-M3 dead

                  Originally posted by momaka View Post
                  By the way, I think I have a motherboard here that needs a Southbrdige replacement as well (SB overheats as soon as PC is powered On). I think the SB on my board was a 82801, but I would have to check. If it is, would you like another project board? Or if not and you don't need the removed 82801, perhaps I'll send you a PM
                  Check that southbridge part number. All 82801 chips are NOT the same. You must look at the two letters after 82801 for a match. The grid patterns and number of pins is different.
                  Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

                  Comment


                    #10
                    Re: Elite 945GCT-M3 dead

                    The bottom heater of the MetCal MRS-1100 seems too small for a desktop board. I have an IR6500 and it's too small as well, it's doable but not comfortable at all. The IR6500 is a garbage station but the cheapest you can get here that can get something done, but I killed my fair share of board anyway… (before I had this station with a small bottom heating element and a 898D and after I got it as well due to the boards bending way too easily)

                    I do the little nudge as well, and it often happens that I can nudge the chip on one side but one specific corner still has a couple of balls not melted as the heating is not uniform at all (I have like 10°C difference between opposite corner of a standard BGA chip). The nudge has to be very gentle not to damage the pads under those balls.

                    Indeed all ICH southbridges from Intel are 82801 chips. The first letter gives the generation (from ICH1 to ICH10) and the second letter the variant. On a given board you have to use the exact same southbridge that it came with.
                    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

                    Comment


                      #11
                      Re: Elite 945GCT-M3 dead

                      Thank you for the informative reply. I was looking at possibly purchasing IR rework stations, the 872, 860, and 6500. Looks like all would be inadequate. I was also wondering if the MetCal 1100 would be better because it is a hot air station rather than an IR station. Any comments on that?????????????????

                      It would be so much better to simply find a commercial business that would handle BGA rework for small quantity users like me. I don't have very many boards that would need rework. I just hate throwing something away if there is any possibility of fixing it. And now the smart phones are taking over and making the desktop computers obsolete!
                      Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

                      Comment


                        #12
                        Re: Elite 945GCT-M3 dead

                        Originally posted by everell View Post
                        Indeed this was my first attempt at southbridge BGA replacement. I experimented with a lot of temperature profiles before starting. I removed the BGA chip on three practice boards before attemping the replacement on this one. All three came of nicely without damaging the board, and cleaned nicely using solder wick and special flux for BGA chips.

                        After removing the BGA chip from this board, it looked much different. There were large globs of solder on the PC board, very different from the previous three boards. After cleaning the board, I found numerous circuit traces damaged. Also several large areas of solder mask had been burned off.
                        Hmm.. so maybe someone did work on it indeed. I find it strange, though. Most repair shops don't do this kind of work. But maybe someone was experimenting with it.

                        That said, it is possible to tell sometimes if someone had done BGA work (or reflow) on a board - particularly if it's done with one of those China IR rework machines. What I noticed about boards being reworked with IR is that the PCB often becomes darker around the BGA chip that has been reworked. However, if the board was reworked with a hot air machine (both for top and bottom heat), then there may not be any darkening of the PCB. Pretty much all of the BGA work I do now as a hobby (typically failed video cards) on my gas burner/stove combined with a hot air gun, I get almost no PCB darkening (unless the rework area is very near the edge of the PCB - then the edge of the PCB gets slight browning.) For temperature monitoring, I use one of those $5 type-K thermocouple thermometers (Lutron TM-902C) from eBay / AliExpress. Not a great setup, but it often gets the job done.

                        Originally posted by piernov View Post
                        I do the little nudge as well, and it often happens that I can nudge the chip on one side but one specific corner still has a couple of balls not melted as the heating is not uniform at all (I have like 10°C difference between opposite corner of a standard BGA chip).
                        Yes, I've had that issue as well. Thus, sometimes I don't always center the BGA chip under the heater, but move it accordingly to where there may be thicker ground/Vcc traces. And on video cards, I always make sure the top and bottom heat points are not to close to the PCI-E connector - otherwise sometimes I get popcorned PCB near the PCI-E traces, while the GPU chip still hasn't reached proper temperature.

                        Originally posted by everell View Post
                        I was also wondering if the MetCal 1100 would be better because it is a hot air station rather than an IR station. Any comments on that?????????????????
                        Hot air is indeed generally better than IR. However, hot air stations typically use more power than IR to get the same work done, due to not all of the heat form the hot air transfering to the board - i.e. IR is more efficient in transferring heat to the PCB/BGA chip. On the other hand, the problem with IR is uneven heating: darker surfaces with a rough finish will get a lot hotter than smooth shiny surfaces. And so components on the board may heat a bit more unevenly (whereas hot air heats everything the same, obviously with things getting the most heat near the hot air source.) IR also tends to darken PCBs most of the time. Hot air, usually no.

                        So regarding your MetCal station: I think it's very good. But you may have to play around with the profiles, temperatures, and heating times a bit to be able to work on larger boards. If you have a gas stove, consider using that for your bottom heater and the MetCal hot air wand as the top air heater. Should be able to tackle anything with that setup. But your wife / other better half may not appreciate you using the stove for your projects now.

                        Originally posted by everell View Post
                        And now the smart phones are taking over and making the desktop computers obsolete!
                        Yes, unfortunately. Much of the younger generation doesn't see a need for a desktop (some even don't think a laptop is necessary! ) - all because everything now can be done through your phone nowadays... until you break it or someone steals it. And even then, people don't want to learn all the advantages they can get of owning a proper desktop PC. Everything has to be mobile and "on the go"... which is a shame, because you often lose a lot of features for the advantage of mobility (which sometimes isn't even needed.)

                        Originally posted by everell View Post
                        Check that southbridge part number. All 82801 chips are NOT the same. You must look at the two letters after 82801 for a match. The grid patterns and number of pins is different.
                        Yes, indeed. Otherwise, I also have an "82801" SB from a Dell OptiPlex GX260 (Pentium 4 era) board... and I checked - it is indeed quite different in size and function from the one I am trying to replace (Dell Inspiron board from LGA775 era with GM33 or GM41 chipset, I think.) Will check and let you know. PC is in the garage under a pile of other PCs... so have to dig a bit to get to it.
                        Last edited by momaka; 03-25-2019, 06:12 PM.

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                          #13
                          Re: Elite 945GCT-M3 dead

                          Got it: the Southbridge on mine is AF82801J1R. Motherboard is ASUS/Pegatron IPIEL-RN2. But I just noticed on a recent test that the SB doesn't overheat if I don't have any RAM in the PC. SB voltage rail is present, though. So it may not be a SB issue, after all. Will create a new thread and post all the details there. Figure it makes sense to see if the issue really is the SB or not before trying to replace it.

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