This board was cleaned before I got to see it but it looks pretty clean. Probably a spill though. Has 1.8V on CPU. 3.4 on SMC_LID. No chime. No light flash on USB keyboard. Doesn't respond to PRAM reset. No 3.3V on PP3V3_S0SW_LCD_UF. Not sure where to look next.
Pin 3 his at 3.4V. PLT_RST_BUF_L is at 3.4V also. So, based on your last suggestion, even with no signs of life with the USB keyboard light, this has reached the SPI ROM stage? In the meantime I'll start the process of checking all of those traces and resistors.