[SOLVED]820-3476 PPBUS low no power

[aurel476]

no liquide damage, just customer used magsafe 45W, no power from charger and battery PP3V42_G3h present 3.41V and ppbus_g3h 0.6V tried magsafe 60w same pb already checked U7100 pin 17/18 and 27/28, smc_bc_acok 3.3v

 

[aprendiz]

Resistance to GND on PPBUS_G3H?? Voltage on PPBUS_G3H??

 

[aurel476]

PPBUS_G3H 0.6V resistance to gnd on PPBUS_G3H and PPVBAT_G3H_CHGR_REG short to gnd 0 ohm short to gnd CHGR_CSO_R_N, CHGR_CSO_P_N

 

[aurel476]

short on pin 2 of F7140

51 ohm cpu coils to pin 2 of F7140

3.75 kohms PP3V3_S5 coils to pin 2 F7140

PP5V_S5 30k ohms coil to pin 2 of F7140

inject 1v to pin 2 of F7140 nothing hot

 

[dukefawks]

Inject voltage and monitor current. At 2 amps something must get hot. This bus is normally 12V so you can go a lot higher.

 

[aurel476]

yes find bad capacitor C7582 now another problem PP3V42_G3H 2.5V and no green/orange light, Q7010 very hot, replaced and always hot

no short to gnd pin of Q7010

 

[dukefawks]

Resistance to GND on 3V42? Voltage on pins of D7005?

 

[aurel476]

voltage on pins D7005

1 : 11,7V
2 : 12V
3 : 12V

resistance to GND on PP3V42 11.1 Kohms

 

[dukefawks]

Inject 3V on 3V42 rail and monitor current draw.

 

[aurel476]

inject 3V, current 0.24a find smc hot replaced now i've green light / orange light and no fan spin not power on

PP3V42_G3H 3.42V and PPBUS_G3H 12.61v

SMC_BC_ACOK 3.39V

SMC_RESET_L 3.39V

PP3V3_SUS 3.34V

Already checked resistance SPI Bus Series Termination, next step diodmode without U6100 ?

 

[dukefawks]

I don't get your logic. You say this was not water damaged so why check U6100?

If this really "just" happened it would have been because of a garbage Chinese charger and 3V42 spiking or something. An issue with PPVRTC/clock chip is more likely then.

 

[aurel476]

Ppvrtc_g3h 3.3v

 

[dukefawks]

Green/orange light present? SMC came from identical donor board?

 

[aurel476]

Yes présent smc identical donor 820-3476-a

 

[dukefawks]

This board had a voltage spike, so many things could be dead. It could really be anything

You could check for power cycling on the S0 rails

 

[aurel476]

Okay that's what i thought , thanks anyway

 

[aurel476]

Yes i will Check power cycling want say voltage pulse ?

 

[dukefawks]

Just want to know if it is cycling/pulsing.

 

[aurel476]

PP1V05_S0 2.7mV

PP1V5_S0 0V

PP3V3_S0 0.183V

PP5V_S0 0v

PP5V_S0_FET 0.6mV

PP3V3_S0 0.182V

no pulse no cycle :/

I do not know if it's normal to L7630, continuity 1 beep / second and stop one beep and stop loop, (without chargeur plugged of course)