Seller Note “Is not working – when card is on PCI-e slot PC is not turn on”
- Resistances at first – Clear short on the PCI-E 6 pin
- Resistances Now
- VCore – 0.6
- VMem – 42.4
- PEX – 103
- 1.8V – 5.8K
- 5V – M+ high!
- 3.3V – 40K
- 12V – 7M+
- Luckily, there was no damage and I had the required shorted high-side MOSFET on a donor card. The replacement went well and the card is now fixed 🙂
Investigating the 12V short
There are 3 VCore VRM phases, the high-side MOSFET on the bottom one has a lower ESR reading than the others and it’s gate reads low ~7 ohms rather than the 10K Ohms on the other two phases.
Use about 100 deg C preheater and 400 deg C hot air to cleanly remove the faulty MOSFET. Then I proceeded to clean the old solder off and add leaded solder to the pads. Luckily, I have a damaged old GTX 970 donor board with the required MOSFET.
After replacement with the donor MOSFET, there are no shorts and the gate reads 10K like the others.
For reference, the memory switching regular is:
- The card seems to be doing very well, maintaining temperatures in the 60s during testing.
- Kombuster & Furmark HD – fine.
- Subnautica Below Zero – fine.
- Heaven on ultra – fine.