820-3115 Green light but ?not turn on

[Dewanbd]

PM_SLP_S4_L =3.3v stable if trigger then 2.4v

 

[2informaticos]

2.4V at PM_SLP_S4_L is good enough to enable all S3 voltages; check if all present.
Check the same for S0 voltages, if PM_SLP_S3_L goes also high.

 

[Dewanbd]

I tried to swap good bios after that now i see no green even i swap again original bios still no green light , PPbus G3H is 12.23v. This is a nightmare now.

 

[2informaticos]

Check for ripped/moved resistors near BIOS chip...

 

[Dewanbd]

NO RIPPED/MOVED register near bios.
I checked the following value
PPBUS_G3H = 12.26V
PP3V42_G3H = 3.48V
SMC_RESET_L = 3.3v
SMC_BC_ACOK = 3.4V
ADAPTER_SENSE = 3.4V
P3V3S5_LL = 0V
SMC_ONOFF_L = 3.4V

 

[2informaticos]

Check if BIOS chip is correctly soldered; pay atention to its orientation.

 

[Dewanbd]

BIOS chip is correctly soldered 100%. This is not too small component , perfect orientation. looks very good.

 

[2informaticos]

Put back original BIOS and report...

 

[Dewanbd]

i put it back origianl Bios and get back green light for while when reconnect it no green light

PP3V3_S3=0v
ppbus-G3H=12.26v
PP3V42_G3H at C6908=3.49v
SMC_BC_ACOK_VCC=3.49V
ADAPTER_SENSE=2.9V
SMC_ADAPTER_EN ( Q7920 PIN2)=0V

 

[2informaticos]

Pins 4 & 5 of U6900 should have both same high voltage, equal with central pin of DCIN board.

"ppbus-G3H=12.26v"
SMC doesn't talk with ISL6259, or something else blocks the I2C bus.

Are you sure about using original Apple 60/85W charger?

 

[Dewanbd]

This is known good original adapter.
Pins 4 & 5 of U6900 have both same 3.48v ( before it was wrong)
so what should i check next

 

[2informaticos]

Do you have same voltage at central pin of DCIN board?
Check continuity from U6900 to it.
SMC_RESET_L voltage?

 

[Dewanbd]

SMC_RESET_L =3.41v
central pin of DCIN board=3.46v
Check continuity from U6900 to it. is ok
Now I see green light. but not turn on.

 

[Dewanbd]

Green light is off when plugin 60w adapter
Green light is on when plugin 85w adapter
Both times no fan spinning.

 

[2informaticos]

Did you try to start in SMC bypass mode?

 

[Dewanbd]

Not start in SMC bypass mode ,
central pin of DCIN board v goes down rapidly 0 v and up 2 v , cycle.

 

[2informaticos]

If central pin voltage is not stable, there is no good conection to U6900, pin 5.
Pins 4 & 5 of U6900 aren't stable too?

 

[Dewanbd]

Pins 1 U6900 =3.48 TO 3.0V isn't stable
Pins 4 & 5 of U6900 =3.47v to 2.9v aren't stable too
I think some component got loose connection bcs it was working unit after i changed hinges cover then this problem arise.

 

[2informaticos]

Post U6901 voltages,
Check solders and traces for U6900/01.

 

[Dewanbd]

U6901 voltages:
pin 1/2=2.87v
pin4=3.49v
pin5=3.49v
solders and traces for U6900/01 are ok.
When i plug in it become orange and after few minutes no light.