I got this Gigabyte Aero RTX 4060 where it initially wouldn't get detected, after disassembly i found that U504 (12v to 5v) was corroded at pin 1 together with it's ADJ resistors, i swapped them for close enough ones (it goes to a 1.02k resistor > 340ohm then 0hm > GND), i installed a 1k and 300ohm one and got 5v properly, fans would spin fine but card still wouldn't get detected, i've measured PEX present then found out that FBVDDQ was missing entirely, analyzing further, U15 was shorted at it's VCC pin (7), at the time i didn't have another exact model but got a TPS51211 instead, i checked...

Have you found anything related? i got the exact same issue.