No I don't think so, the top three legs are the same. But the oxidation between the bottom leg end the top three legs can be the problem.
Try to clean the board again. (demineralized water + PCB cleaning fluid 10:1)
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SMC Issue on MBP 13 - Hardware Troubleshooting Guide
- Thread starter Dadioh
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No I don't think so, the top three legs are the same. But the oxidation between the bottom leg end the top three legs can be the problem.
Try to clean the board again. (demineralized water + PCB cleaning fluid 10:1)
My problem was also water damage, short to ground on 12v rail. I found burnt cap and after replacing that I've got steady 12v with battery but flucturating voltage with magsafe. After all day trying to find problem, replacing all components, there was no problem at all. Started mac with battery only and SMC reset solved fluctuating 12v, now is steady. Funny story, but after long busy day you jut forget about some simple things.
I don't know if you posted here some details about your board, but it would be useful to post pictures and your current measurements. Also board view and schematics if you have. I can take a look on that.
Thank you for your willingness to help. It's a Macbook Air A1370 mid 2011 (820-3024) i5 processor, 2GB RAM. Last time I replaced some missing wire around the charger IC. That was a real challenge
I will post pictures later. (I have no time to work on it at the moment)i see lot of oxidation also on the lvds connector. clean whole board with isopropil and a super soft brush.
Hello,
I'm new here and I found this a nice source of information.
Thanks for sharing!
I have done some repairs on different Macbooks and they are all almost the same of setup
What I was wondering about is how the startup procedure is (detailed) it would make falt finding much easier.
I know it all starts withe the G3Hot 3.45V
it powers the U7000 baterry charger and the SMC (and some other stuff but those are the main)
But then? Please correct me/update this info if I'm wrong
The SMC starts, and what does the SMC do next
First start the S5 rail by making P3V3S5_EN_L low (FET does not conduct anymore)? or does it first check the SMC_BC_ACOK from the U7000?
After that, does it wait for P5V3V3_PGOOD? (it seems not because the 5V part of U7200 is on the S3 rail)
where comes the power button and what does the SMC do after pushing the power button?
I think when there is a good understanding of the startup sequence of the SMC, you can easaly find where to look just by the behaviour of the Macbook when you apply the magsafe and push the button.
So could someone help me out a bit?
I'm new here and I found this a nice source of information.
Thanks for sharing!
I have done some repairs on different Macbooks and they are all almost the same of setup
What I was wondering about is how the startup procedure is (detailed) it would make falt finding much easier.
I know it all starts withe the G3Hot 3.45V
it powers the U7000 baterry charger and the SMC (and some other stuff but those are the main)
But then? Please correct me/update this info if I'm wrong
The SMC starts, and what does the SMC do next
First start the S5 rail by making P3V3S5_EN_L low (FET does not conduct anymore)? or does it first check the SMC_BC_ACOK from the U7000?
After that, does it wait for P5V3V3_PGOOD? (it seems not because the 5V part of U7200 is on the S3 rail)
where comes the power button and what does the SMC do after pushing the power button?
I think when there is a good understanding of the startup sequence of the SMC, you can easaly find where to look just by the behaviour of the Macbook when you apply the magsafe and push the button.
So could someone help me out a bit?
I realized I better spend some more time with a toothbrush. I've read a lot of people using 97% Isopropyl Alcohol (IPA) but I haven't had any luck finding it. I have 91% right now and got that at a Walgreens.
Where can I find some PCB cleaning fluid?
Dead(?) Late '08 15" MBP
I received a Late '08 15" MBP that would not power on at all (no workarounds or anything) and I don't know its background.
I can connect the MagSafe and the green "charged" light comes on, and I know the battery is fully charged because the charge indicator displays all of the green dots. I also have 3.467 V on G3Hot. I opened up the machine and took out the logic board when I first got it and it had a decent amount of corrosion on the right side of the processor side of the logic board as well as at the center of the bottom edge on the same processor side of the board. I didn't see any problems on the side of the board facing the bottom plate. The thing that concerned me is that what seemed to be causing most of the corrosion was a small, button-cell looking battery near the RAM slots. When I measured that battery for power, I got .055 V (almost nothing). I pressed on, however. After a good scrubbing with some alcohol and a toothbrush, the corrosion looked gone. I let the alcohol dry and put it all back together. I did an SMC reset just out of habit and plugged in the MagSafe. The light turned green. I tested the battery with the buttons on the side. The lights all lit right up. Everything was looking great! I pushed the power button....
Aaaaaannnnddddd...........
NOTHING.
What can I possibly do other than pay for Apple to replace the board or buy a board myself and replace it?
BTW: Shorting G3Hot does not power up the machine. Also, when cleaning the MBP, I used alcohol that was labeled "Isopropyl alcohol (95%) in a glycerin solution (5%)." Would this have messed anything up?
One last question: Does anyone have info on the "battery" or what it does? Is it like a CMOS battery on PCs? Can you replace it?
I received a Late '08 15" MBP that would not power on at all (no workarounds or anything) and I don't know its background.
I can connect the MagSafe and the green "charged" light comes on, and I know the battery is fully charged because the charge indicator displays all of the green dots. I also have 3.467 V on G3Hot. I opened up the machine and took out the logic board when I first got it and it had a decent amount of corrosion on the right side of the processor side of the logic board as well as at the center of the bottom edge on the same processor side of the board. I didn't see any problems on the side of the board facing the bottom plate. The thing that concerned me is that what seemed to be causing most of the corrosion was a small, button-cell looking battery near the RAM slots. When I measured that battery for power, I got .055 V (almost nothing). I pressed on, however. After a good scrubbing with some alcohol and a toothbrush, the corrosion looked gone. I let the alcohol dry and put it all back together. I did an SMC reset just out of habit and plugged in the MagSafe. The light turned green. I tested the battery with the buttons on the side. The lights all lit right up. Everything was looking great! I pushed the power button....
Aaaaaannnnddddd...........
NOTHING.
What can I possibly do other than pay for Apple to replace the board or buy a board myself and replace it?
BTW: Shorting G3Hot does not power up the machine. Also, when cleaning the MBP, I used alcohol that was labeled "Isopropyl alcohol (95%) in a glycerin solution (5%)." Would this have messed anything up?
One last question: Does anyone have info on the "battery" or what it does? Is it like a CMOS battery on PCs? Can you replace it?
Try to short the power on pads! Shorting the G3Hot rail will not power up the computer
Always use pure 99% alcohol (or the highest percent available). Also try to avoid old stock alcohol because the old alcohol's PH is possible acidic and will make more problem.
That battery is the CMOS battery, you can replace it (or just disconnect it at the moment).
do you have 3.3 volt on 3.3 volt coil ?I received a Late '08 15" MBP that would not power on at all (no workarounds or anything) and I don't know its background.
I can connect the MagSafe and the green "charged" light comes on, and I know the battery is fully charged because the charge indicator displays all of the green dots. I also have 3.467 V on G3Hot. I opened up the machine and took out the logic board when I first got it and it had a decent amount of corrosion on the right side of the processor side of the logic board as well as at the center of the bottom edge on the same processor side of the board. I didn't see any problems on the side of the board facing the bottom plate. The thing that concerned me is that what seemed to be causing most of the corrosion was a small, button-cell looking battery near the RAM slots. When I measured that battery for power, I got .055 V (almost nothing). I pressed on, however. After a good scrubbing with some alcohol and a toothbrush, the corrosion looked gone. I let the alcohol dry and put it all back together. I did an SMC reset just out of habit and plugged in the MagSafe. The light turned green. I tested the battery with the buttons on the side. The lights all lit right up. Everything was looking great! I pushed the power button....
Aaaaaannnnddddd...........
NOTHING.
What can I possibly do other than pay for Apple to replace the board or buy a board myself and replace it?
BTW: Shorting G3Hot does not power up the machine. Also, when cleaning the MBP, I used alcohol that was labeled "Isopropyl alcohol (95%) in a glycerin solution (5%)." Would this have messed anything up?
One last question: Does anyone have info on the "battery" or what it does? Is it like a CMOS battery on PCs? Can you replace it?
check also vga coil if shorted as it is very common for 15 inch 2008 macbook
I received a Late '08 15" MBP that would not power on at all (no workarounds or anything) and I don't know its background.
I can connect the MagSafe and the green "charged" light comes on, and I know the battery is fully charged because the charge indicator displays all of the green dots. I also have 3.467 V on G3Hot. I opened up the machine and took out the logic board when I first got it and it had a decent amount of corrosion on the right side of the processor side of the logic board as well as at the center of the bottom edge on the same processor side of the board. I didn't see any problems on the side of the board facing the bottom plate. The thing that concerned me is that what seemed to be causing most of the corrosion was a small, button-cell looking battery near the RAM slots. When I measured that battery for power, I got .055 V (almost nothing). I pressed on, however. After a good scrubbing with some alcohol and a toothbrush, the corrosion looked gone. I let the alcohol dry and put it all back together. I did an SMC reset just out of habit and plugged in the MagSafe. The light turned green. I tested the battery with the buttons on the side. The lights all lit right up. Everything was looking great! I pushed the power button....
Aaaaaannnnddddd...........
NOTHING.
What can I possibly do other than pay for Apple to replace the board or buy a board myself and replace it?
BTW: Shorting G3Hot does not power up the machine. Also, when cleaning the MBP, I used alcohol that was labeled "Isopropyl alcohol (95%) in a glycerin solution (5%)." Would this have messed anything up?
One last question: Does anyone have info on the "battery" or what it does? Is it like a CMOS battery on PCs? Can you replace it?
This is my life right now..
I think yours and my system are well past the point of being saved by some alcohol and a toothbrush, and are in need of physical chip replacement.
Where do you guys even get these replacement chips anyhow?
Try to short the power on pads! Shorting the G3Hot rail will not power up the computer
I meant the power pads.... At least I think I did.... My research found that the power on pads were just above the ODD connector. Is this not the correct place? (see attached image)
Where is this located? I have searched through most of the thread and I have found some info on the coil itself, but nothing on the location to measure which would allow me to test this coil.
Where is this as well? I can't find anything in this thread about this "vga coil." (or online even, really)
I can't. The battery seems to be permanently connected to its holder with a solder tab.
Gahh, this seems to be a never-ending chain of disappointment.....
Attachments
I have a problem with 2 MPB's both C2D K24. Both with the sam problem it won't start.
When I measure the voltages they are all there and correct, G3H is there, the G3 1.8V is there , the S5 3V3 is ther, 1V05 S5 is there.
but when I push the power button, nothing happend.
I found out that both PM_SLP_S4_L and PM_SLP_S3_L are low, so it stays in sleep mode.
The Sleep mode is controlled by the MCP79 (NVIDIA), how can I get it out of sleep mode?
Thanks in advance.
Make it 3 now
When I measure the voltages they are all there and correct, G3H is there, the G3 1.8V is there , the S5 3V3 is ther, 1V05 S5 is there.
but when I push the power button, nothing happend.
I found out that both PM_SLP_S4_L and PM_SLP_S3_L are low, so it stays in sleep mode.
The Sleep mode is controlled by the MCP79 (NVIDIA), how can I get it out of sleep mode?
Thanks in advance.
Make it 3 now
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A1278 13 2012 Keyboard Trackpad not recognised
This forum has been really insightful so and I'm hoping someone could help me with this issue.
The keyboard and trackpad are not recognised at all on my 13" A1278 2012 MacBook Pro, which is odd as the power button still works without issue. Everything else functions normally, except that the keyboard and trackpad are completely unrecognised (no mouse movement at all, no keys work).
I have tried a PRAM reset using a USB keyboard, running Apple Diagnostics (which found no issues whatsoever), I've cleaned the logic board thoroughly with isopropyl and a toothbrush (the MacBook had suffered liquid damage, got it second hand), and I have tried replacing the trackpad and cable (which remained completely unrecognised, it is now in another MacBook and works 100%).
I have also tried installing a fresh copy of Yosemite to no avail.
![a1278.png~original]()
I have tried to read the schematics for my machine and I see that the Keyboard and Trackpad are using this U5701 component, maybe there is an issue with that?
How do I find this component on my logic board? I have tried to read the codes on the components but I can't see U5701 anywhere.
Any advice would be greatly appreciated,
Thank you!
EDIT:
The board is the 820-3115-B model.
This forum has been really insightful so and I'm hoping someone could help me with this issue.
The keyboard and trackpad are not recognised at all on my 13" A1278 2012 MacBook Pro, which is odd as the power button still works without issue. Everything else functions normally, except that the keyboard and trackpad are completely unrecognised (no mouse movement at all, no keys work).
I have tried a PRAM reset using a USB keyboard, running Apple Diagnostics (which found no issues whatsoever), I've cleaned the logic board thoroughly with isopropyl and a toothbrush (the MacBook had suffered liquid damage, got it second hand), and I have tried replacing the trackpad and cable (which remained completely unrecognised, it is now in another MacBook and works 100%).
I have also tried installing a fresh copy of Yosemite to no avail.
I have tried to read the schematics for my machine and I see that the Keyboard and Trackpad are using this U5701 component, maybe there is an issue with that?
How do I find this component on my logic board? I have tried to read the codes on the components but I can't see U5701 anywhere.
Any advice would be greatly appreciated,
Thank you!
EDIT:
The board is the 820-3115-B model.
Last edited:
They are at least 4 models..... 820-XXXX number please
1. do you have schematics and board view?
820-3115-b
Hi, sorry, it is the 820-3115-B model.
I couldn't get the Boardview to work with EAGLE or Allegro Cadence (tried on both PC and Mac, but I might be retarted).
Hi, sorry, it is the 820-3115-B model.
I couldn't get the Boardview to work with EAGLE or Allegro Cadence (tried on both PC and Mac, but I might be retarted).
Last edited:
This one is working on my mac with wineskin:
laptopserviz.bg/media/wysiwyg/Allegro_Free_Physical_Viewer_15.7.zip
I have them but 10x,
I minded do YOU have them but any way try to find "landrex boardview". it is somewhere in earlier treads. it works on windows but on mac you need wine.
Now do you have 3,3 v on R5704?
Is R5704 1,5 ohm?
Is R5703 220K?
Measure also R5714=470 ohm, R5715=10K.
What voltage do you have on them?
If everything is OK, than I think you will need to replace U5701.
I have seen it go bad many times after liquid damage on the keyboard.
Have you try to measure the resistance between ground and the Inductor for BGA (L8920), recently I use to have the same problem as yours and came to be short in Q8950 and Q8951.
Logic Board does not start
Hello everybody.
I need help.
Sorry for my bad English.
I have a logic board 820-3115 where I get stuck.
Magasafe lights green but always goes on off on off. :-/
When I press power button turns the fan and the CPU cooler is warm.
There is no picture and no chime.
I turn in circles here. Maybe I'll start with you again in front of.
Hello everybody.
I need help.
Sorry for my bad English.
I have a logic board 820-3115 where I get stuck.
Magasafe lights green but always goes on off on off. :-/
When I press power button turns the fan and the CPU cooler is warm.
There is no picture and no chime.
I turn in circles here. Maybe I'll start with you again in front of.
got the error found for the blinking of the Magsafe.
Power supply is broken.
It Starts still do not.
I measured times.
CHGR_UGATE = 16.8 volt
CHGR_PHASE = 16.8 volt
CHGR_LGATE = 16.8 volt
PPBUS_G3H = 16.8 volt
this is all very high.
should I replace the U7000 or could be the fault of another component come