So long story short. I have bought used MSI RTX 3070 ventus 3x OC that was artifacting and showing 0mb memory. I have tried reflashing bios but that didnt help 
I have used MATS to check memory and the results you can find in the file attached. Card looked brand new and there was no any dust particles on it and has factory seal.
When unscrewing i have noticed that factory seal was put on top of the old one so that means msi was working on it in some way. After opening it i have noticed that one of the vram chips is discolored like a lot of heat was put on it and that corresponds to MATS more than less
so i have removed it and im planning to order new vram to soldered it back. My question is should i replace all 4 of them even the ones with small errors or maybe this errors are there because of that faulty vram??
Can anyone give me some clue on that. Thanks

I have used MATS to check memory and the results you can find in the file attached. Card looked brand new and there was no any dust particles on it and has factory seal.
When unscrewing i have noticed that factory seal was put on top of the old one so that means msi was working on it in some way. After opening it i have noticed that one of the vram chips is discolored like a lot of heat was put on it and that corresponds to MATS more than less
so i have removed it and im planning to order new vram to soldered it back. My question is should i replace all 4 of them even the ones with small errors or maybe this errors are there because of that faulty vram??
Can anyone give me some clue on that. Thanks