820-3437-B MBA 2014 no power

[lincev]

hi i have this board with magsafe led green led orange but no power or fan spin. Either power in smc bypass mode

PPBUS_G3H = 8.53V
PP3V42_G3H = 3.39V

SMC_RESET_L = 3.36V

PP5V_S5 = 4,97V
PP5V_S0 = 0V

ALL_SYS_PWRGD = 0V

PP3V3_S5=3,26V
PP3V3_SUS=0V

U7501

23 = 8.53V
22 = 3.26V
12 = 3.39V
13= 1.97V
29 = 4.97V
21 = 3.39V

any ideas? thanks

 

[2informaticos]

"PP3V3_S5 = 0V
--------------------
P3V3_S5=3,26V"
???

 

[lincev]

sorry I check again only mistake is right 3,26V

copy the tests from another board with the same fault

 

[lincev]

diode mode to ground

L7560
1 P3V3_S5_REG_L=369 value
2 PP3V3_S5_REG_R=369 value

 

[2informaticos]

"PP3V3_SUS=0V"
What about PM_SLP_SUS_L?

Check SMC_ADAPTER_EN, PM_DSW_PWRGD, PCH_DSWVRMEN, PM_BATLOW_L and the 4 PCH's (DC) RTC signals.

 

[lincev]

PM_SLP_SUS_L=0V

SMC_ADAPTER_EN=3.36V
PM_DSW_PWRGD=3,39V
PCH_DSWVRMEN=3.28V
PM_BATLOW_L=3.29V

PCH RTC Signals:
PCH_INTRUDER_L = 2.99V
PCH_INTVRMEN = 3.18V
PCH_SRTCRST_L = 3.28V
RTC_RESET_L = 3.28V

 

[2informaticos]

Any history available?

Post PM_PWRBTN_L, PM_RSMRST_L, SMC_ONOFF_L voltages.
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L (at same time).

 

[lincev]

Well, please excuse me, I was going to take these steps and suddenly the computer turned on (maybe because it was without any power supply all weekend)

The same thing happened to it about a year ago, but on that occasion it only took a day to work and we thought it was overheating.

Thank you all the same