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[SOLVED]820-3115 logic board

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vaswaniraj

New member
Hi Team,
Today morning received a Macbook Pro with 820-3115 logic board.
The customer complained that last night he was watching a movie and then it just shut down, so he thought it was the battery and kept it to charge the whole night, but the computer will not come on this morning.
When the computer came to me I did the following :
1. Tried disconnecting the battery and connect the computer directly with the magsafe adapter - The computer came on - but after the Apple Logo the computer shuts down after reaching almost 10% of progress bar.
2. Another thing I observed is that though the battery indicator ( push button on the side ) showing that the battery is full but the computer does not come on by pressing the power button on battery power. Only when the magsafe adapter is plugged in then only the computer gives the chime.
3. I thought probably the hard drive is failing hence the OS is not loading, so I tried to boot the system from an external drive, but with that as well the progress bar reaches to almost 10% and then the system just shuts down. The fan stops spinning.
4. The computer only comes on when the magsafe is connected and after it comes on
 
V

vaswaniraj

New member
Hi Duke, The logic board is absolutely clean and has no corrosion anywhere. The reason why it took me so long to reply is because I wanted to make sure there is nothing that I not checked as far as corrosions is concerned. Please advice further.
 
jessa

jessa

New member
How can we eliminate variables to simplify the problem? Question: Will a normal 820-3115 board by itself, out of any housing, make the fan spin and the speaker chime?
 
V

vaswaniraj

New member
peterfixit I don't care who laughs at me or not. I am here to learn. Even if I am bullshitted I am not giving up. This is my bread and butter. Yes I know I am a slow learner, but will never give up.
 
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V

vaswaniraj

New member
[USER][/USER] Definitely the board 820-3115 has a problem. The board out of the housing makes the fan spin and does not shut down as it does when back into the housing. So I am wondering why is it that when the board is out of the housing does not shut down, but when put back into the housing comes on and shuts down after 10% of progress bar is done.
 
S

SMMRepair

Member
Ask yourself: "What case assembly components are capable of making the board turn off?" Now combine the answer to that question, with this one: "Why does the board stay on when I remove it from the casing assembly?"
 
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peterfixit

peterfixit

New member
were not really laughing at you, we want you to think, you didnt think about anything before posting, you haven't watched even the basic logic board repair videos, I only joined this forum to help other people and to get their help with my previously unfixable boards, I dont just post, hey bro my board isnt working what should I do, people on here are not going to tell you step by step what to test because louis has already done this several times on his channel
 
jessa

jessa

New member
vaswaniraj said:
[USER][/USER] The board out of the housing makes the fan spin and does not shut down as it does when back into the housing. So I am wondering why is it that when the board is out of the housing does not shut down, but when put back into the housing comes on and shuts down after 10% of progress bar is done.
Click to expand...

Wondering why is great. Now translate that into a test. Consider each thing that plugs into the board a variable. How can you figure out WHICH variable is the one that is the problem?

Remember what I always say "You don't have a board problem until you KNOW you DON'T have a parts problem."
 
V

vaswaniraj

New member
Hi Jessa, I appreciate you and Louis helping me understand this. Now I have a another problem. I figured out that when the trackpad is plugged in the original problem of the computer starting up and then shutting down occurs. Now I encounter a different problem. The computer only comes on when the magsafe adapter is plugged in. It does not come on when the power button is depressed, though the battery is full. Is this a one wire circuit problem, or is it the battery and the battery indicator creating this problem. I shall try to troubeshoot with a new battery, but your feedback shall help me diagnose the problem faster. Thanks. Raj.
 
V

vaswaniraj

New member
Hi team, - Can someone please give me a hint, what is that I am not doing correct.
As mentioned earlier - I disconnected the Trackpad and now the computer does not shut down.
Now the computer does not come on by pressing the power button.
I even tried to put this logic board into another housing, and in that housing it comes on with the press of the power button.
I mean I want to learn but then I don't understand what is the reason I am getting stuck.
I don't want Plz bro solutions.
But ask me questions which I will answer and give me some hint and that way I would learn.
The computer comes on if the MagSafe charger is connected.
Thanks Raj.
 
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V

vaswaniraj

New member
Hi Team,
I think i figured out what the problem is.
As I mentioned earlier that the trackpad is causing this problem. I also think ( correct me if i am wrong ) that the keyboard is connected via the trackpad. So if the trackpad is disconnected the keyboard also does not work. While the machine is one and if i connect the trackpad, the keyboard becomes active but as trackpad seems to have a problem, it just shuts the machine down.
I have a machine from which i can pull a good know trackpad and see if that solves the problem.
Will keep you guys posted.
Thanks again.
Raj.
 
V

vaswaniraj

New member
Here is my work around and findings.
I had a good working trackpad, which I installed it on the machine.
The machine continues to shut down if the new trackpad is connected to the logic board.
I think this problem is related to the SMC.
I shall check the following voltage rails tomorrow and get you the feedback.
PPBUS_G3H
PP3V42_G3H_REG
SMC_RESET_L
SMC_PM_G2_EN
Will check on U7000 as well.
Will also check current sensing resistors.
Will also try to run an ASD on the machine tomorrow.
Am I going in the right direction..... ??
 
V

vaswaniraj

New member
PROBLEM SOLVED.
Hi Louis / Jessa / Duke.
I am sorry for not using my brains. I don't know why I feel scared, while I am troubleshooting the problems. Now in this case as Jessa pointed out "You don't have a board problem until you KNOW you DON'T have a parts problem." In my case it was the keyboard and I was thinking that it was the board. I think I have too many things on my plate and that is the reason I am not able to concentrate. So I decided that I am not going to rush anything and first I would definitely use my brains to troubleshoot what the problem is. Put my findings and then if I am unable to troubleshoot I will come to this forum.

I promise I will use my brains from now on. Even if I am wrong I will try.

Thanks once again.

Regards,

Raj.
 
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