Gigabyte Windforce R9 290X GV-R929XOC-4GD

December 21, 2021
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Seller Note “Gigabyte Windforce N770 OC: Not working, for parts only. No any idea what is wrong”

Summary

  • The Ebay seller was either mistaken or lying! On inspection of the board this is not a Gigabyte Windforce N770 OC, but instead one of these https://www.gigabyte.com/Graphics-Card/GV-R929XOC-4GD#ov
  • Screws in bad condition, some missing evidence of being dismantled in a rough way! Luckily cheapish, but not a good start in analysis..
  • Thermal pads in very poor condition, dirty.
  • Still, didn’t find any obvious shorts and the main resistances seemed in range, so perhaps there is hope yet.
  • I have another RX290X in seemingly better condition Gigabyte R9 290X GV-R929XOC-4GD (Card B)
  • Resistances
    • 12V
      • PCI (measure at F4) – 4.15K
      • PCI-E (measure at L601) – 2.1K
      • PCI-E (measure at L602) – 39.6 (was 327 on my other 290X, so seems 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) – 104.8 (158 on other 290X, possibly a bit low)
    • VCore (VDDC) (measure at any of 5 phases L502/3/4/5/6) – 1.1 (was 2.4on my other 290X)
    • VDDCI (measure at L500/507) – 18.1 (was 35.4 on my other 290X)
    • VMem (MVVD) (measure at L700) – 203 (was 242 on my other 290X)
  • I find the lower memory and core related resistances compared to my other RX 290X a little concerning (VRM chip is ELPIDA W2032BBBG-6A-F)
  • I also don’t know why fuse F4 is missing? The pads look poorly soldered, would be lucky if a fuse is all that’s wrong! Usually, they blow for a reason, but there is no short on that 12V as far as I can see…

PCB Missing Component / Damage

Here is the missing component area:

R9 290X Missing Fuse F4

I don’t have a schematic, but a fuse can be seen in this position from a marketing photo:

Windforce R9 290X Fuse

It appears some kind of PCB repair has been attempted:

  • Could be the pads were damaged/replaced.
  • The area is sticky and patterned, perhaps flux residue.

I was initially concerned there was a nearly shorted capacitor on first investigation (C1326) shown below:

R9 290X C1326

Update 23/07/2022

However, this capacitor is not actually shorted. I can now see one end is ground and one end is VDCCI (18 Ohms).

Apart from the rather low 12V (L602) rail, I think it’s worth replacing that missing fuse to see what voltages we can get. After doing so, strangely I can see most voltages apart from MVDD (shows 0.01V), which is similar if not the same as the fault on my other R9 290X! I think I will wait for parts and try replacing the VMem (MVDD) PWM controller. I have less hope for this card compared to the other one (lower resistances might hint at a core issue, no firm evidence), but it could still be worth resolving the VMem rail for the learning and chance it might work.