Summary
- Felt lucky as it was sold as a RX 580, hopefully it will turn out lucky 🙂
- Resistances
- VCore – 0.8Ω
- VMem – 28.5Ω
- VDDCI – 24.5Ω
- Display Rail – 20.1Ω
- 5V – 507.3Ω
- 1.8V – 3.9KΩ
- 3.3V – 2.3KΩ
- 12V – K++Ω (slot) 0.8Ω (ext) Short on 8 pin, 6 pin 2.3KΩ
- Hmm.. the other card like this with a similar short had savage burns making it scrap. This one doesn’t , but we’ll have to see whether the core got fried as a result of that 12V short.
Investigating the 12V short
Well, this card has 8 phases in the VCore VRM and the top one has a suspiciously low resistance of 2.8Ω on it’s gate, the others all have 8.68KΩ. That makes the MOSFET Q2 (QA3111 https://pdf1.alldatasheet.com/datasheet-pdf/view/1242145/UPI/QA3111N6N.html) my suspect.
I’ll try removing it to see if the short clears.
OK, the 8 pin PCI-E now measures a healthy 3.2Ω, but is the core ok…? Well, I’m getting ahead of myself, the core stayed cold, as there is no VCore voltage, all others are present.
Next to investigate why the vcore voltage is missing.