Gigabyte R9 290X GV-R929XOC-4GD (Card B)

May 14, 2022
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Seller Note “Faulty”

Summary

  • It’s this one https://www.gigabyte.com/Graphics-Card/GV-R929XOC-4GD
  • Overall, seems like quite a nice example
  • This cards measurement took some understanding for me, luckily I found a PDF that helped tell the different rails apart
  • Resistances
    • 12V
      • PCI (measure at F4) – 4.15K
      • PCI-E (measure at L601) – 2.1K
      • PCI-E (measure at L602) – 327 (seems a bit low?)
    • 5V (measure at U400 or F400) – 3.8K
    • 3.3V -398
    • 1.8V (Created at U350, measure C357/8/9) – 213.6
    • Display Rail (0.95V) (created at U300, measure at L300) – 158
    • VCore (VDDC) (measure at any of 5 phases L502/3/4/5/6) – 2.4
    • VDDCI (measure at L500/507) – 35.4
    • VMem (MVVD) (measure at L700) – 242
  • VRM chip is ELPIDA W2032BBBG-6A-F
  • Voltages
    • Vcore – 0.91v
    • Vmem – Missing
    • VDCCI – 0.99v
    • Display rail – 0.91
    • 5v – present
  • Possibly just a memory VRM power issue, resistance is quite high good to compare with my other one Gigabyte Windforce R9 290X GV-R929XOC-4GD. Could be the other one is best used as a donor board, depending on the extent of it’s PCB damage.

Investigation missing MVDD VMem Rail

Gigabyte r9 290X – MVDD PWM Controller

PWM is NCP 5230 https://www.onsemi.com/pdf/datasheet/ncp5230-d.pdf

VCC measures 12V – OK

Enable measures 1.85V, hopefully enough.

PGood is about 0.01V

It would be a simple conclusion to assume the controller is faulty, but I might try measuring the low and high gate signals.

R733 (High gate resister)

R719 (Low gate resister)