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Текущее время: 29 июн 2024, 16:16
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Страница 1 из 1 [ Сообщений: 18 ] |
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Pandemonium6
[ТС]
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Заголовок сообщения: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 17 дек 2021, 10:28 |
Продвинутый форумчанин |
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Зарегистрирован: 22 июл 2021, 03:06 Наличности на руках: 1,139.72
Сообщения: 761 Откуда: Holand
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Всем привет,
I got this card for repair. It had 3 ohms on memories but I located 4 MLCC capacitors on the back which were making a short circuit (KZ) on the memory power. These capacitors looked like exposed to the moisture. This VRM worked under this almost "KZ" state. I replaced capacitors (no thermal image for this condition, sorry)
The memory resistance went back to 95 ohms but this card has very hot memory chokes and it consumes more power on the memory power phase. Everything looks good, all resistances are good, voltages are good, nothing else shines on the thermal cam, bios is being read and was reflashed. Even 1.8V is perfect ~900 ohms. VCORE is initially ~0.9V and goes to ~0.76V when the post code reaches b2. PEXRST works perfectly.
But the card is looping, going to b2, stays there for 20 seconds and retries to initialize card without restarting a computer. I managed to get picture maybe twice for a few hundreds of attempts and even MATS finished and PASSed but only twice. Now it only goes to b2 and again and again.
What do you think friends? Is the GPU dead? Almost a hundred ohms on the memory but such power consumption? Memory controller? GPU looks good on the thermal cam on the top, no hot spots.
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 17 дек 2021, 12:08 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): The memory resistance went back to 95 ohms This is normal. I think you must use oscilloscope to check all phases PWM signal on GPU and memory at first. Also you need check (with oscilloscope ) all other power.
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 18 дек 2021, 12:41 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): What is the purpose of this circuit? This is a "discharge circuit" - for an instant emergency shutdown of the memory voltage, in some cases, it follows the signal to turn on the memory power. This circuit, moreover, very often misleads beginners - since the Q577 transistor remains OPEN even after all power supplies are turned off, and when checking the memory resistance, the multi-meter will show a short circuit - although it is just an open transistor that remains open for about 10 minutes after the board is turned off. Pandemonium6 писал(а): some capacitors and they started to glow in the thermal cam as crazy Leaky capacitors do not always get very hot - with a partial short circuit, they can short-circuit the power in the presence of voltage, practically not heating up. But more and more points to the failure of the GPU. GP102 are very sensitive and very often fail at the slightest reason.
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Pandemonium6
[ТС]
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 18 дек 2021, 18:31 |
Продвинутый форумчанин |
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Зарегистрирован: 22 июл 2021, 03:06 Наличности на руках: 1,139.72
Сообщения: 761 Откуда: Holand
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This is very informative post, thank you I thought it was for starting a VRM when it is not loaded to address a light load and possible startup problems. This 10uF in the gate was also strange as it kept this transistor conducting for a long time. This capacitor can be discharged by a reverse leakage of double diode and body diode of the Q576 and a leakage in general. Now it is obvious CatSW писал(а): But more and more points to the failure of the GPU. Yes, ~100 ohms in static condition without power and overcurrent when powered on. This does not smell good. I have seen glowing single memory many times with a good resistance when cold but it is not the case here. Memories look uniformly warm.
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 18 дек 2021, 20:20 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): This is very informative post, thank you My pleasure Pandemonium6 писал(а): Memories look uniformly warm. You can desolder all the memory bank and check the GPU with "MATS -e 1" = this key testing memory IN GPU (internal cache). If memory in GPU (cache) is well - you will see PASS w/o ANY memory onboard.
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Pandemonium6
[ТС]
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 19 дек 2021, 06:36 |
Продвинутый форумчанин |
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Зарегистрирован: 22 июл 2021, 03:06 Наличности на руках: 1,139.72
Сообщения: 761 Откуда: Holand
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Thank you for the tip but the owner wants to sell it for parts on Ebay to another naive buyer This is mystery when it resurrect from time to time the MATS passes. He will not pay for experiments with 11 vrams anyway. I would have to solder them back after tests, no way The problem is that this card does not initialize, it goes to the "almost beep" and stays there for 10-20 seconds and initialization starts over. Initially it looked as an easy repair with some capacitors in "KZ", failure as always very easy to spot. Resistance from 3 ohms went back to normal. There is another theory that there is corrosion under the GPU or in deeper layers and GPU sits in a software loop trying to do something with memory controller and it consumes extensive energy. I hate to reball GPU because from a minor fault I can cause total failure just because only heating the chip and because it doesn't help in most cases.
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 19 дек 2021, 13:15 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): wants to sell it for parts on Ebay to another naive buyer Pandemonium6 писал(а): I hate to reball GPU But you can only heat the GPU up to 230C with flux - without removing it, this will remove possible corrosion under it. And it will save you the necessary chip reball. Or without doing anything, sell this board as it is - there are enough naive buyers
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 20 дек 2021, 01:39 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): Maybe I will reflow it anyway. I have everything for IR soldering. Sounds great, good idea! Give this GPU a chance
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 20 дек 2021, 12:05 |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): After reflow the card became undetected This shouldn't have made her work worse - perhaps there were short circuits under the GPU. Need full reball GPU((.
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CatSW
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Заголовок сообщения: Re: Gigabyte 1080 Ti Gaming OC 11 GB Добавлено: 22 дек 2021, 19:00 |
Пользователь |
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Зарегистрирован: 02 июл 2019, 17:52 Наличности на руках: 690.75
Сообщения: 490 Откуда: Одесса
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Pandemonium6 писал(а): It's a Rabbit hole. I can't afford more time. Yes, it makes sense. Good luck with your next repairs!
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Страница 1 из 1 [ Сообщений: 18 ] |
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