Yet Another 820-00164 Fan Spin No Boot

[iambehr]

Hello,

Board in S0 state confirmed by checking all power rails. CPU Vcore 1.8v.
Fan spins normally for 10 seconds and then kicks in to overdrive.
No display or other signs of life.
ALL_SYS_PWRGD is present 3.4V.
PLT_RESET_L is high.
No light on USB device at all.
Resistance to ground at L7320 and L7310 17.5 ohms each.
U1900 is getting proper power, as well as u6100.

Any ideas where to start?

 

[2informaticos]

Any history?
Check all traces and resistors around U6100.
If all OK, try new BIOS.