I still needed a heatsink to my ASUS GTX 580 and when a suitable GPU appeared I immediately jumped the gun and bought it. It had supposedly working cooling and didn’t display anything. Let’s see what’s wrong with it.
Firstly, check if the seller was right.
And unfortunately he was. No picture, fans work, not recognized in linux, however what seller didn’t mention is the fact that GPU didn’t heat up much. Usually a bad sign – bad core, bad voltage rail, bad VBIOS.
Disassembly revealed that the core was both delidded and damaged in the process. Fortunately damage seems minimal and I quite don’t believe that it could result in no video / cold GPU.
Then I began measuring resistances – PCIE 12V OK, 3.3V OK, EXT 12V OK, core was a little lower than usual at ~0.3 Ohms instead of 0.5Ohm (as long as it’s not directly shorted it’s usually fine), VRAM 0.2Ohms, …
…
Hold up. VRAM rail is shorted. Standard procedure in such case is to hook up a lab PSU and find the place that heats up.
That’s exactly what I did and obviously there were complications – nothing heated up.
Such behaviour can be explained in only one way – something can soak up this heat, which means that it’s either the core, VRAM IC or PCB has some mechanical damage on VRAM voltage plane.
Closer inspection revealed that one VRAM chip was replaced.
After lifting that IC I saw carnage, unfortunately on data pins, so in order to fix this GPU I will need a microscope and some replacement pads. Overall due to lack of both of these things I can’t this card for now. However I won’t steal parts off of it for now.
In the meantime I managed to put my GPU and heatsink from the broken GPU together.
Quick message to Mr. Seller – I appreciate Your honesty in selling a product that is not in “unknown” condition, but being transparent in the description is equally important – previous repair attempts are quite important to know of.
If You want to avoid ripping pads from the PCB then be patient. A bit higher heat on Your HA machine ( I use ~350-375°C) for a bit longer. These IC are VERY resistant to heat over temperature, besides if an IC is broken it doesn’t really matter if it becomes “more” broken. These ICs, when heated to ~230°C will be extremely easy to remove, as the only thing holding them onto the PCB will be gravity and solders surface tension.
Thanks for reading!