820-00840 doa

[crea2k3]

I have a 820-00840 here that is just over a year old. The customer has taken it to Apple and they said the motherboard is dead. I have inspected both sides of the motherboard. I cant see any water damage, although there was a tiny amount of corrosion on both ends of C8400, no short is detected on that cap. When the charger is plugged in no fans spin, at the battery terminals the voltage is 0 volts when the charger is plugged in.

I have taken some readings near u7000 and this is what they were :
PPDCIN_G3H_CHGR @ 7020 = 20.32V
PPVIN_G3H_P3V3G3H @ U7000 = 20.07V
PPVBAT_G3H_CHGR_REG @ U7000 = 0V
PD_SMC_CBC_ON @ U7000 = 0V
SMC_CHGR_INT_L @ U7000 = 3.4
DCINVSENS_EN_L @ U7000 = 19.79V
SMC_RESET_R_L @ U7000 = 3.4
PPVCCCPU_S0G = 0.00v

 

[2informaticos]

If you get 20V at R7020, means SMC is working; 3V3_G3H OK and SMC_RESET_L too.
But you didn't post exact voltage for PPBUS_G3H (F7000).
Also need to know if 3V3/5V_S5 appear; if yes, check xV_SUS voltages too.