2012 MBP 820-3332-A Not turning on

[KootenayMacGuy]

Hello. I have a 2012 Retina MBP A1398 Board 820-3332-A that fails to power on.
There is a green light on the charger (turns to amber)
All voltages are present except for PP5V_S4 and PP5V_S5 on U7201.
P3V3S5_EN is Present
No PM_SLP_S5L
No SMC_S4_WAKESRC_EN

There are no shorts to ground on any lines on U4900 or U7201
Bad U4900? Bad CPU?

Any help is appreciated

 

[2informaticos]

Test the board alone on the desk.
Post diode mode at 5V_S5.
Do you get 3V3_S5?