820-3115-B board only works on SMC bypass mode

[sangolossyfon]

Board has no sign of life, but does spin fan max speed in SMC bypass mode. But even in this mode it has no sign of life- no display etc. No shorts on any 5V/3.3V rails. G3H voltage 13.33V. Draws 0.6 watts in when plugged in (no fan) and 5W when plugged in and in SMC bypass mode (full fan).
SMC Bypass mode- CPU_VCORE and PLT_RESET_L both at 0v.

 

[2informaticos]

Be sure R7402/3 have correct ohm values.
Also check their solders and traces.

Check SMC_DCIN/PBUS_VSENSE levels, as SMC_DCIN/BMON_ISENSE too.

 

[sangolossyfon]

they are correct at 150/182k

In regular (non smc bypassed) mode while plugged in-
SMC_DCIN_VSENSE- 2.2v
SMC_DCIN_ISENSE- 0.73v
PBUS_VSENSE- 1.55v
SMC_BMON_ISENSE- 0v

 

[2informaticos]

"SMC_DCIN_ISENSE- 0.73v"
This looks very high!

Check resistance (ohm scale) over C7020.
R7021/2 are the first suspects.