820-00928 20v, 0v ppbus no short

yair37

Member
water damage, clean all no shorts ppbus 0v usb 20v
usb was 5v and after 10sec get 20v i was replaced D6950 and now 5v 2sec and then 20v
j6951 was damage, now its o.k.
i was replaced ISL 3 time but the same..
ppbus 390 0.2v
SCL 300 , SDA 400 on J6951
 

yair37

Member
if i do it right(no battery, 10sec PB then put the charger and release PB after 10sec) so still 0v PPBUS
 

2informaticos

Administrator
Staff member
Try to release power button after 6-7s.

Without battery, charger alone, USB-C inputs switch to 20V (in normal mode)?
 

2informaticos

Administrator
Staff member
When tested in SMC bypass mode, should go to 20V, 2-3s after SMC_ONOFF_L is released.

You may have problems with some signal not good from USB-C to SMC; or even something wrong around U7000.
 

yair37

Member
I was notice that QB300 and QB400 probably was get hot (they Brown color)..
PPDCIN_G3H 150 20V
PP20V_USBC_TB_VBUS_F 150 20V
UPC_TB_GATE1 150 20V
TP_BQ400_DRAIN 150 20V
UPC_TB_GATE2 600 0V
 

yair37

Member
on a good working board:
PPDCIN_G3H 500
PP20V_USBC_TB_VBUS_F 170
UPC_TB_GATE1 780
TP_BQ400_DRAIN 520
UPC_TB_GATE2 750
 

yair37

Member
u7000 voltage compare to good working board:
TBA_COMP 1.1V 2V
TBA_CSO_P/N 0.5V 12.6V
TBA_LX2/1 0V 12.6V
PPVBAT_G3H_CHGR_REG 1.2V 12.6V
SMC_CHRG_INT_L 0V 3.4V
 

yair37

Member
signal from USB-C this what i dont understand....what to look and what can Couse that?
UB400/300 Q300/400 for example...or what lines..
i have good board to check but i dont know what to search :|
 

2informaticos

Administrator
Staff member
I faced this problem with bad SMC_USBC_INT_L signal only.

Try checking/comparing voltage and diode mode to ground on other lines going to SMC...
 
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