We Thought it Was a Lost Cause - Another RTX 4090 Saved From Major Damage

hello everyone and welcome to Christmas Germany in this video we have another 4090 the card was used with water book and the image come from leak in the water system customers ended here with the water book he also described that he cleaned the cart and he dried the cart in oven for a couple of minutes or hours I'm not sure but the cart is not baked so at really wore temperature just to dry the PCB this is not bad and day after the customer takes me one more time and say that his motherboard is also damage and he's hoping that the cart is still working and his system is not posting because the motherboard damage and he also said okay you can change the thermal pads and send the card back to me if if it's working and I now took the card to change the thermal pads to clean it and I decided to measure what is going on here because we are not sure if the cart is working or not and look what I find out let's do the measurements together one more time we're going to start with the 12 volts from the PCI SWOT they're looking good the 3.3 is okay first pair of data lines in the front are okay moving to the 12 plus 4 pin connector shorted shorted and the next coil is also shorted uh 503 over here on the bottom side looks good on the back side we need PEX reset pin and a reference clock plus and minus same reading very good let's switch to resistance mode okay let's measure the memory start from there and we have 2 ohms exactly the same reading as our 12 volt rail coming from the power supply let's measure it one more time 2 ohms 0.1 and here again 2 ohms 0.1 so this means that something is shorting the 12 volt with the memo radio which is very bad and this something is uh fit a mosfet driver mosfet and here on this card we have a place for four but we have three one here one here and one here and one of those three driver mosfets is short in our 12 volt with the memory rail this can kill the GPU and Fry all the memory chips but we have to find out let's continue with the pixel here on the bot on the top side 25 ohms first 1.8 volt rail 0.8 K and the second one shorted this one should be around five to seven hundred ohms but here we have one ohm as you saw in the last video we had almost the same symptoms like here shorted 1.8 in shorted memory but here we have one bonus shorted 12 volt rail I'm really skeptic about this card right now because shorting 12 volts with the memory almost always uh the card is dead completely dead but let's give it a chance and try to fix it I will use a thermal camera from here inject voltage in the 12 volt inductor here and we will monitor what is getting hot in this area and let's inject one volt in our 12 volt power supply input right over here on this coil and we will monitor this area where we have the GPU chip we can also see all all driver mosfets for the memory Rail and all RAM chips injecting one volt right now and as you can see we have one of the RAM chips and this is a C1 I think is getting hot one more time injecting one volt and again the same chip in the middle is getting hot all right the thermal camera showed us we have a short circuit so hot spot right over here exactly on this area this is our bank C1 here on the corner and I can already see a little bit of discoveration on the surface exactly where the thermal camera showed the hotspot I'm not really sure if you can see it but for me it's visible and our next step from here is to remove this round chip and hopefully this will solve our problem with the shorted 1.8 volt reel right over here and from there we have to find out which driver mosfet is shorting our 12 volts with the memorial we have three options one over here this one over here no visible damage as you can see and we have one more here on the bottom side without visible damage foreign [Music] [Music] chips removed as you can see right here it's no longer on the board I have cleaned already the pads and the board is a little bit warm hot not warm hot but we can take the multimeter props and start measuring the 1.8 volts and now we have 513 and Rising which is very good checking the memorial 13 ohms and also Rising so this one ram chip was causing our problem with the memory and 1.8 volt rails to short now they're free and we are safe here we have one more problem to go and this is the most important one our 12 volt from the power supply as you can see it's no longer two ohms now it's 13 and Rising exactly the same like our memory rail exactly the same reading because they are shorted together and this is not good and our board now let's go down to the room temperature and we can use the thermal camera to see uh which one of those three driver mosfets is shorting the 12 volts with the memory rail but we have a problem and the problem is that we cannot inject uh one more than 1.3 volts right here on those coils because if I inject here for example five volts I will kill the GPU chip I will kill the RAM chips and this card is done our maximum right here is to inject 1.2 1.3 volts these are completely safe voltages they will cause no problems on the GPU chip and also the RAM chips But Here Comes our problem if we inject 1.3 volts here the memory is working on 1.3 volts also and nothing will happen let me show you that under the thermal camera let's inject uh 1.3 volts here on those two coils it doesn't matter which one I will choose this one 1.3 volts and uh taking a look what will get hot injecting voltage right now as you can see absolutely nothing because we don't have power consumption this is the same voltage as the memorial and the memory is working on this voltage there is nothing getting hot all driver mosfets are staying cold let's see what options we have uh to find which driver mosfet is 40. option number one is to remove the driver mosfets one by one and measuring the 12 volt inductors right here after each mosfet option number two is to remove the inductors after the driver mosfets one by one and again measuring the 12 volts option number three it and this is my option is to use again the thermal camera but in order to make something hot I need electricity to flow there we don't have a electricity wall here because the voltage is the same as the working voltage on the memory Rail and that's why I have to create it for example if I short something after the inductors for the memorial if I short one of the RAM chips or if I short one of the capacitors here this will create a flow right here on this area we have a missing driver mosfet missing inductor and capacitors there there is place for one capacitor like this one right here like this one right here and this one right here I can share that with my screwdriver right here I can short that this is completely safe for the card it will cause no damage to the other components just shorting this area here and injecting again the same 1.3 volts or lower this will work as well one volt will also work we can see under the thermal camera what is getting hot so let's try that and here we have it this is completely enough for me shorting this area injecting voltage showed us that this driver must fit here on the top side is causing our problem and let's fix it [Music] thank you [Music] and now we have the tower driver mosfet soldered this is a new one and don't worry about this solder bow this those pins are the same line and this is a exactly our 12 volt coming from the power supply which was shorted so let's cool the board down and measure one more time starting with the 12 volts from from the power supply we have kilo ohms and Rising this time which is perfect checking the memory layout 50 and Rising and 1.8 516 Rising those readings are now normal everything looks very good I will not solder a new round chip right now here on this place because I want to test the card first with short circuit like this almost always the GPU chip is dead now we have our 4090 plugged in like a secondary device and we can try to see if the card is recognized from the system let's attempt the BIOS information and we have information about the BIOS which means that our card is here and our card is recognized let's see the training status warnings warnings fail on C1 because it's missing and that's it we are good to go we can solder on your arm chip there and hope that the cart is working and the memory controller is not damaged and after soldering the ram chip here is the board already cooled down and there is the ram chip on Place everything looks good we can take the multimeter props and as usual measuring the memory rail 30 and rising and 1.8 also very important after changing the ram chip 515 Rising everything is still good so let's pull the card in like a primary device and test it one more time and this time we have picture from the car the cart is recognized of course and we can see the training status one more time let's check that and now everything looks perfect no errors beautiful very good I'm very happy about this card because after this uh serious damage shorted memory with the 12 volts not many cards are able to survive that and now I will go to clean the the board in Ultrasonic Cleaner assemble the water block and test the card further in Windows for now the tests are showing that there are no problems the card is working normally we don't have a problems with a memory controller on or the memory chips every measurement is looking good the question is can a short circuit like this cause damage to the GPO chip the answer is yes but we cannot measure that we cannot see that it's impossible only the time will show very interesting is that last week I had almost the same case like this card but the card was from gigabyte and there was shorted power stage right here on this corner completely burned power stage and again short circuit with a 12 volt from power supply and the memory rail I was thinking this is no way no way everything is most likely burned here I clean the area I change the the driver mosfet cleaned everything and guess what the card also was working unbelievable and now the second one I don't know what is going on with the 4000 serious cards but with the previous cards 2000 series and 3000 Series if there was a short like this everything was dead but this is very good the customer should be happy and now a little bit information about the customers in our webshop uh we will no longer sell antique Fox and the reason is very simple because I don't use it if I don't use something I don't want to sell it to you if I don't like something I don't want to sell it to you that's why we're keeping only in stock the airsoftworks this is great Fox for hand soldering I think the best one on the market it's a little bit expensive but there is nothing better than this and for BGA work reballing soldering big chips like gpos RAM chips um for solder both this one is the best one if 8300 from interfox and you should try this one if you need repair check the links in the video description if you need parts for your projects check our shop GPU fix I hope you learned something today and we will see you in the next one bye foreign [Music]

Channel: KrisFix-Germany

Views: 25,651

Keywords: krisfix, krisfix germany, 4090 repair, 4090 error 43, 4090 black screen, rtx4090, 4090, gpu repair, video card repair, graphic card repair, rtx4090 memory error, rtx4090 artefacts, gpufix.de, repair, video card, broken video card, how to fix graphic card, how to fix video card, graphic card doesnt work, broken graphic card, graphics card repair, gpu, rtx 4090 first, 4090 first impresion, overclocking, Liquid Metal, liquid metal 4090, dead 4090, 4090 water block, 4090 mistake

Id: ITQxIFUca2k

Length: 15min 26sec (926 seconds)

Published: Sun Apr 16 2023