820-00875 A1708 no power 20v with 1.88amp

hello i recieved this macbook with wifi ic burnt after i removed the wifi ic still cant on and cpu is getting hot.
fan on's for 50 seconds but no display and no usb activity no chime.

voltages:
ppbus_g3h 13v
PP3V3_G3H 3.4v
PP3V3_S5 3.3v

PM_PWRBTN_L 3.3v
PM_RSMRST_L 3.3v
PM_BATLOW_L 3.3v
PM_DSW_PWRGD 3.4

when triggering SMC_ONOFF_L drop pulse at PM_PWRBTN_L at same time from 3.3v-0.3v
PM_RSMRST_L 3.3V steady

PM_SLP_S5_L 3.3v
PM_SLP_S4_L 3.3v
PM_SLP_S3_L 3.3v
PM_SLP_S0_L 3.3v
PM_SLP_SUS_L 3.3v

L7210/20 0.9v
L7410/20/30 0.6v

PCH issue???
 

2informaticos

Administrator
Staff member
L7210/20 voltage should drop to 0.6V, when board boots.
Is strange to get 0.6V at L7410/20/30; as iGPU is not powered until high graphics load is detected.

Whatever damaged U3700, could damage PCH too; there is direct connection PCH-U3700.
 
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