we refurbish this 820-00840 before selling it out to customer, about 2 month later customer complains that it randomly shuts down. 1 week about ~3 times.
we took back the laptop and now it does not boot at all.
Found out that when battery is not plugged in, it boots fine with just charger
Battery + charger = no boot, charger loops after charger hits 20V and goes back to 5V.
Battery only = no boot.
measuring on battery terminal itself i get 0V but if i measure the cells i get 11.8V. Battery lock up, but same case when using known good battery.
when on only battery, ppbus is pulsing about 12v(can't get a good ready from osope) 2 short pulse within 1sec and 2/3 sec of no activity and loops.
Measure current sensing for ISL R7061/R7062 and all is good, measured SMB_SMC_CHGR_SDA and SCL and i get normal communication with SMC(diode reading at 0.395)
not sure what else is wrong here
we took back the laptop and now it does not boot at all.
Found out that when battery is not plugged in, it boots fine with just charger
Battery + charger = no boot, charger loops after charger hits 20V and goes back to 5V.
Battery only = no boot.
measuring on battery terminal itself i get 0V but if i measure the cells i get 11.8V. Battery lock up, but same case when using known good battery.
when on only battery, ppbus is pulsing about 12v(can't get a good ready from osope) 2 short pulse within 1sec and 2/3 sec of no activity and loops.
Measure current sensing for ISL R7061/R7062 and all is good, measured SMB_SMC_CHGR_SDA and SCL and i get normal communication with SMC(diode reading at 0.395)
not sure what else is wrong here