820-3476 macbook pro

[[email protected]]

a 3476 macbook pro it has the orange light on the charger and all the rails are present except SMC_SENSOR_PWR_EN.

 

[2informaticos]

Can you explain what is the problem with this board?
No video, no USB activity???
Try to start in SMC bypass mode.

 

[[email protected]]

The actual problem is that SMC_SENSOR_PWR_EN on pin2 of Q5480 is missing
Q5480 pin 3 is 0v, p4 12.58v and p5 12.4 and p6 12.58

 

[2informaticos]

"No video, no USB activity???
Try to start in SMC bypass mode."

The board is working and only missing SMC_SENSOR_PWR_EN???

 

[[email protected]]

no the board doesn't turn on. and these two rails are missing PP1V35_S3 and SMC_SENSOR_PWR_EN

 

[JohnB8812]

Ok you have way more than missing SMC_SENSOR_PWR_EN forget about that rail. Voltage on PPBUS_G3H? PPVRTC_G3H, PP5v_S5, PP3v3_S5, PP3v3_SUS, PP5v_S4 present???

 

[2informaticos]

You've fixed the atention in something irrelevant at this point...

"and all the rails are present"
Post the ALL then...

 

[[email protected]]

Thanks for your replay al these rails are present
PPBUS_G3H
PPBUS_S5_HS_COMPUTING
PPBUS_S5_HS_OTHER5V
PPBUS_S5_HS_OTHER3V
PP3V42_G3H
PPVRTC_G3H
PP5V_S5
PP5V_S4
PP3V3_S5
PP3V3_S4
PP3V3_SUS
PP3V3_S3
PP3V3_S4_TBT
PP1V05_SUS

and these rails are missing:

PP3V3_S4SW_SNS
PP1V35_S3
PP1V35_S3_CPUDDR
PPVTTDDR_S3

 

[JohnB8812]

Exact voltage on PPBUS_G3H???

 

[[email protected]]

ppbus_g3h is 8.85v

 

[2informaticos]

"8.85v"
Do you mean 8.58V???

"PP3V3_S4SW_SNS
PP1V35_S3
PP1V35_S3_CPUDDR
PPVTTDDR_S3"
You've posted other S4/3 voltages as present; so these ones should also be present.
Check for short on any of them.
An o-scope should help to catch a pulse at least, if present...

 

[[email protected]]

I checked for a short but there is no short on these rails

 

[2informaticos]

Start then to check powers and enable for all these S3 supplies which don't deliver tension.
PM_SLP_S4_L is present, but some resistors derivate this signal to enable various supplies.

 

[[email protected]]

could it be that Q5480 gone bad? because i get nothing on pin 1/2/3 and only on P4 12.58v p5 12.45 and p6 12.33v

 

[2informaticos]

When you have doubt about any sensor, try to start on SMC bypass.
As you got S4 voltages, board is starting.
Check if all coils pulse at least.

 

[[email protected]]

Sorry but could you please tel me how to bypass SMC?
Thanks alot

 

[2informaticos]

https://www.google.com/search?q=start+smc+bypass&ie=utf-8&oe=utf-8&client=firefox-b-ab

 

[[email protected]]

the board doesn't turn on at all. how can I bypass the SMC?

 

[2informaticos]

Bypass SMC reffers to a way to start the board disabling SMC sensors.
And is explained in the results of the link above mentioned.
Press power button, plugin the charger and maintain power button pressed 5-10s...

 

[[email protected]]

Dear Sir thanks for your replay and I apologize if I ask a silly question time by time, Please take into consideration that board repair is not what I do for living it is my hobby and I'm not learning it on other peoples machines I bought couple of defect macbook/ macbook pro ( these are not donor boards and fixable ) and I'm trying to get them fixed.
and I really do appreciate your time and effort.
And I wish you a very nice weekend ahead.