Hi guys,
I have a Gigabyte GTX 1080 G1 Gaming 8GB gpu. The earlier life of this gpu is unknown.

Fans are spinning on full speed.
All main voltages presents but gpu not detected by motherboard.
The voltage on pin 1 of the bios is constantly 1.8V, so I think the chip select is not happen

Can I checking more something?

Цепи pci-e 16x проверьте, попробуйте через райзер pci-e 1x переделанный на 16 линию.

Можно поподробней?

Did u use a oscillograph?
- Quartz generation?
- Bios reading process

Did u check the 3.3SEQ voltage?

Скорее всего нужен ребол чипа

Yes, I have oscilloscope.
What do you mean on "Quartz generation"? Ichecked the Vcore with oscilloscope.
Bios reading process is mising. :(
3.3SEQ voltage is OK, I checked on R1045.

I replaced the quartz but nothing changed. :(

1st , i think you need to make sure, your device manager device HW ID is correct or not, if HW ID incorrect, GPU is unknow is exptected , and you need to read schematic for layout bios design, especially STARP 0- xx