EVGA GTX 760 SC w/ ACX 4Gb

June 26, 2022
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Seller Note “Artefacts”

Summary

  • Rare 4Gb edition, with artefacts reported I was hoping for a fixable VRAM issue. However, this is a somewhat unusual case in that the VMem rail is reading on 4 Ohms, so not a classic case of running MATS and replacing the faulty chip.
  • Resistances
    • VCore – 6.3Ω
    • VMem – 4Ω! (once shorted chip was replaced, 94 Ohms)
    • PEX – 243Ω
    • 5V – 500Ω
    • 3.3V – 884Ω
    • 12V – 2KΩ and up
  • There are also multiple smashed-off capacitors
  • Used thermal camera highlight warmth with 1V injected
  • Replaced the shorted VRAM chip, Elpida W2032BBBG-60-F fortunately I had some spare!

Finding the short

Because the short is low (4Ω) and not a dead short, I thought hopefully it could be a VRAM chip or IC, rather than a shorted capacitor or something tragic like the memory controller on the core itself. So, I injected 1.2 volts into the VMem rail, about 2 Amps were drawn and the thermal camera detected warmth in 1 chip and the core area (probably the memory controller).

TODO thermal camera

So, it’s just case of removing the chip and hoping for the best:

Success! After replacing the shorted VRAM chip, the VMem rail has risen to a healthy 94 Ohms!

Initial Testing

  • MATS 10/50/100 Mb – Passed
  • Drivers load
  • Kombuster HD – Passed
  • Great! Don’t want to push the card too far without replacing those capacitors, as there are multiple on the VMem rail that could reduce stability.

Replace missing capacitors

There are some important 01206 capacitors missing from the VMem rail, I need to remove one to work out it’s value then replace them all. There are also some scratches to the PCB, I don’t think they are all the way through, but I should clean the area, possibly add some solder mask and test the DVI ports (that they appear to connect to).

EVGA GTX 760 4Gb – Broken caps and PCB scratches

Replaced with 10uF

Testing

  • Kombuster HD 1080p and even 1440p seem fine
  • In my main PC, nice to use – slight vibration from fans though.
  • Fallout 4 played ok
  • (!) Fortnite crashes every time no matter what settings are selected, plays for a while then the application freezes.
  • Worked fine in my main PC driving 2 monitors for over a week.
  • (!) Fans can be noisy, should replace or discount. Seem ok in another test machine without any supporting bracket.
  • Subnautica running ok – 100% GPU, temp 70