Try to thoroughly clean the AGP connector contacts with a pencil eraser, after thoroughly degreasing with 95% alcohol. And check the auxiliary power contacts. As well as capacitors (For swollen, leaking ones). It is also worth updating the thermal interface. In general, these old cards often have broken tracks inside the printed circuit board and there is no way to fix this (Unless you replace the board itself).

I have done most of those things, also i changed 4 capacitors near power connector.
This is rare card, costs some hundred bucks to buy working one. If i cannot get this fixed, it will go to my Wall of Retro collection 😀
Thank you 😀

1. use a second pci adapter and boot using PCI primary vga.

reboot, reboot...
check if the device still present in device manager. if it is here - check/replace bios chip.

2. if you have oscilloscope, check VGPU and VMEM, capacitors in the power rail, they may be dead.

By the way, yes, try to flash vBIOS again.

PS: Surprisingly, these outdated chips (NV30; NV30GL; NV35GL; NV40; G70) can still be purchased from some Chinese suppliers. As well as suitable memory chips. It remains to do the reverse engineering of the PCB itself. It would be nice if someone launched such a new project to re-release these outdated graphics cards needed for retrogaming under DOS\9x. I would buy several similar video cards, because it is becoming more and more difficult to rummage through junk (There are a lot of really dead video cards or they are about to be on the verge).

dm- wrote on 2024-01-16, 10:10:

1. use a second pci adapter and boot using PCI primary vga. […]
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1. use a second pci adapter and boot using PCI primary vga.

reboot, reboot...
check if the device still present in device manager. if it is here - check/replace bios chip.

2. if you have oscilloscope, check VGPU and VMEM, capacitors in the power rail, they may be dead.

I will test this, thank you of your suggestion.

DoZator wrote on 2024-01-16, 10:20:

By the way, yes, try to flash vBIOS again.

PS: Surprisingly, these outdated chips (NV30; NV30GL; NV35GL; NV40; G70) can still be purchased from some Chinese suppliers. As well as suitable memory chips. It remains to do the reverse engineering of the PCB itself. It would be nice if someone launched such a new project to re-release these outdated graphics cards needed for retrogaming under DOS\9x. I would buy several similar video cards, because it is becoming more and more difficult to rummage through junk (There are a lot of really dead video cards or they are about to be on the verge).

I will download working bios file for this GPU from internet and try re-flash another bios. Thank you 😀

I tested Geforce with another PCI(Voodoo 3) card installed and windows XP shows Geforce in Device Manager and has no issues. I made backup file of Geforce original VGA Bios and flashed another bios and it does the same thing, after first boot, when restart machine it will not "power up" Geforce.