This weeks post is about a request I got. Seller of one of my previous GPUs has reached out to me seeking help with his graphics card. Me being be, I couldn’t pass such an occasion and accepted the request.
This is the patient in question. It’s a Gigabyte GTX 780 with 3GB of VRAM and Windforce cooler.
Mr. Seller said that the GPU works only without drivers, with them he got black screen.
*sniff sniff*
Do You sense that smell?
It smells like… dead VRAM IC.
It’s almost like I did it before. One dead VRAM chip, F0, You don’t see the failing bits there, but all 32 bits are showing errors meaning that whole bank is dead.
Time to take apart the GPU and see if I have suitable VRAM IC to reball and swap. Before I could do that though I got jumpscared.
I was in shock. Apparently Mr. Seller also didn’t know anything about this and bought this GPU as used and not repaired in any way, shape or form.
Yet, it was baked so badly that the glue around the core changed color to browinsh indicating severe overheating. PCB was also harmed, it got bent like a banana around the core.
Intermission
If You, Dear reader, even think about baking your GPU, please don’t do it. It really doesn’t do anything good. This method of repairing electronics was at most semi-viable during the late 2000, when manufacturers used low-tg underfill that, in the long run, caused cracks under the silicon flip chip. There never was a problem with ROHS or lead-free solder.
Look at early PS3/XBOX 360. They could be temporarily fixed by heating the RSX/GPU. It caused increased pressure on the flip chip, “fixing” it for a few days or weeks. The only proper “fix” was to replace the GPU with a high-tg GPU, which would make today a “Frankenstein PS3” (40nm RSX from slim consoles or 65nm ICs) or a retrofitted Xbox 360.
If You don’t believe me then there is an official explanation by Xbox team: link.
Anyway, back to the repair.
I unforunately didn’t have same VRAM ICs to be swapped. Spending any money on this used and abused GPU was not wise.
With my advice Mr. Seller has given up on this card and let me keep it.
But then I started to wonder.
I had a semi-compatible VRAM IC, made by Hynix insead of Elpida, but running on the same speeds and voltages. Only 2 things that were stopping me were likely different RAS/CAS/… timings and potentially broken pads under the VRAM and/or the core.
Since this GPU was already destined to go to the parts bin I took the executive decision to try and “Frankenstein” it.
Here is the final result of my work: straightened PCB, cleaned core and swapped VRAM.
This my first time mismatching VRAM ICs, and it was finally time to see if I made it work or not.
Surely enough IT WORKS!!! No errors on the MATS test. As long as the core doesn’t show any artifacts it’s completely fixed.
Oddly enough my mod works.
It’s absolutely fine.
I informed Mr. Seller about my success and discussed that he wants to still use this GPU. He also wanted me to give it the full service.
I did exactly that. Replaced the dry pads and used a MX-4 thermal paste. While I was at it I also cleaned the cooler from the inside.
With these mods temperature did drop about 3 degrees and Furmark showed 76 FPS instead of 73. Simple thermal paste swap made the core ~4% faster while being ~4% cooler.
Cool.
I deem this GPU fully fixed and back from the realm of dead electronics. I hope it’s going to serve its owner great for years to come.
Thanks for reading!