(347) 552-2258 [email protected]

[SOLVED] No PM_SLP_S4_L on 820-2877

Status
Not open for further replies.
F

Fizzl92

Member
Hello,
Sorry for my bad English.
I have a problem with an older 820-2877 MacBook Pro and I hope somebody can help me with it. The device was water damaged. However, I couldn't find any proof of water inside! I checked the Power Rails and noticed that everything including PP3V3_S5 is ok. But the first S3 Rail (PP5V_S3) isn’t. It's reading is 0V! I checked the beginning of the circuit and noted that the ENTRIP signal for PP5V_S3 is 0V. Pin 2 on Q7221 is 3,3V. That’s why this Transistor sends the ENTRIP to ground I think. I followed this path and saw that this ENABEL come from a Transistor which is closed by PM_SLP_S4_L, which is also 0V on this machine. There is no Short on PM_SLP_S4_L. I've already checked the input and output signals of the PCH which only confuse me. I can't find any other S5 Rails needed for the PCH to turn on (like PP1V05_S5 on other boards do). I'm stuck at this point. I hope you can understand my bad English. It would be really great if someone could give me a hint where I have to Look next.
Tanks!
 
A

aprendiz

Moderator
This is a core 2 duo board, so, no PCH on it...... It does not power on by itself..... Short R5015 pads to power on the board....
 
F

Fizzl92

Member
Hello,
thank you for your answer. I´ll try it tomorrow and hope it will work again. This would mean that the keyboard is damaged and i´m sorry that i wasted your time. if not i´ll let you know. By the way: How can i find out which pads i have to short on which board to turn it on?
 
F

Fizzl92

Member
I really can not believe that I was so dumb. Thats all. It´s working again! Just by shorting the pads. Thank you so much for your help!
Have a nice Day!
Best regards,
Felix
 
Status
Not open for further replies.
Top