SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[rickAC]

Originally Posted by bosna1973

cmdrdata, thank you for your input.
Can you identify this component in red

If your model is A1278 K24 than the component in red is C3500 (pin 1: PP3V3_S3_CARDREADER_DVDD, pin 2: ground.

[iN00b]

Originally Posted by Dadioh

Pin 14 should be a solid 3.4V. If it is fluctuating or not reading 3.4V then the charger circuit is not happy. Most likely cause is the charger IC but you might want to check some of the circuits around the charger with schematic in hand and see if you can determine an issue. Sorry, can't provide a step by step for that because every issue could be different and this level of troubleshooting really requires someone with electronics knowledge.

----------

Welcome back Commander Data

Great to have you back on the thread.

I should pay more attention to what I´m doing I have 3 chargers and 1 of them is for a macbook and the other ones are for MBP. When I tested the voltage with an MBP charger it was ok. I actually tested pins 2,3 and 14 and compared all of them to the voltages at a similar working board and they were all same so the charger circuit should be ok.
After looking the board more thoroughly I noticed that 2 pins of one component have corroded and there is no connection. The pins are the ones marked with green arrows at the attached image. I found the image from previous posts. I´m guessing this might be my problem.
Does anyone know that what the component is exactly and is there a place where I could order these from?

[Dadioh]

Originally Posted by iN00b

I should pay more attention to what I´m doing I have 3 chargers and 1 of them is for a macbook and the other ones are for MBP. When I tested the voltage with an MBP charger it was ok. I actually tested pins 2,3 and 14 and compared all of them to the voltages at a similar working board and they were all same so the charger circuit should be ok.
After looking the board more thoroughly I noticed that 2 pins of one component have corroded and there is no connection. The pins are the ones marked with green arrows at the attached image. I found the image from previous posts. I´m guessing this might be my problem.
Does anyone know that what the component is exactly and is there a place where I could order these from?

That is one of the inrush FETs. If yours is a 2009 MBP13 then the part is shown below. To be certain, check for the other FET on the back of the logic board near that one. If you can read the part number on that it will confirm.

http://avnetexpress.avnet.com/store/...storeId=500201

[Dadioh]

Originally Posted by kennethf

Hello
Great forum
Iam working on a water damaged macbook pro 13 2010 A1278 EMC:2351.
The mac charges the battery and G3hot is good. But it wont start Great if someone could help me out where to look.

Ps I think there something wrong with my 5V supply, where can I find this on the PCB ?

Thanks

The 5V and 3.3V device is identified in the attachment. See schematic for which pins to measure but you can measure them on capacitors coming off the power outputs rather than trying to get the probe on the device pins (risky for shorting).

[Musicsoul78]

Originally Posted by Dadioh

Although electrically the DC-in board is equivalent between the A1278 Pro and the earlier A1278 unibody non-PRO the 2 screw holes to mount to the chassis are slightly different spacing so you can't interchange them.

This is very true!!!
You can not swap them straight over but you can use it for testing purposes.

[Dadioh]

Originally Posted by Musicsoul78

This is very true!!!
You can not swap them straight over but you can use it for testing purposes.

Yes. For testing purposes that would work. I actually had a DC-in from an older Macbook White polycarbonate that I used for testing unibody logic boards. The pinout was the same.

A word of caution when using a DC-in board outside of the case. Wrap it with kapton tape so that it doesn't accidently move around and short something on your logic board. I learned the hard way when the cord yanked it into contact with the logic board I was working on and applied 16V where it should not have been applied. Poof. One dead logic board

[iN00b]

Originally Posted by Dadioh

That is one of the inrush FETs. If yours is a 2009 MBP13 then the part is shown below. To be certain, check for the other FET on the back of the logic board near that one. If you can read the part number on that it will confirm.

http://avnetexpress.avnet.com/store/...storeId=500201

Ok, thanks! And yes - the markings on top of the FETs say: 1127 so it´s the one. Now to get those, hope this works - fingers crossed

[mm9]

Its a great topic. I have read most of it.


Could you please give me a hint on finding this silver square component marked RED from my mobo please?

logic board is apple 820-2915-b
Macbook Unibody 15 inches
i7 - probably 2011


chip is marked with

i "diode triangle symbol" R
9395
2984
1051


Thanks in advance

Mike

[mm9]

I have read many advanced instructions and info here.

Is there a chance that one of you have tried connecting back-light to the motherboard on a Late 2010 Macbook Air without this feature.

I have already added backlight but cant find a place to put a socket powering it. Micro controller should be able to support it but where to look for a spot?

Anyone willing to give it a go?

Best

Michael

[cmdrdata]

Originally Posted by mm9

Its a great topic. I have read most of it.


Could you please give me a hint on finding this silver square component marked RED from my mobo please?

logic board is apple 820-2915-b
Macbook Unibody 15 inches
i7 - probably 2011


chip is marked with

i "diode triangle symbol" R
9395
2984
1051


Thanks in advance

Mike

It is an isolation switch (power FET) made by International Rectifier. The part number is IRF9395. See attached.

[mm9]

Originally Posted by cmdrdata

It is an isolation switch (power FET) made by International Rectifier. The part number is IRF9395. See attached.

Thanks!!!! Great You have made my day. All the best!!!

[docentore]

Hi all, great thread, great help can be found here. I need some help from you guys. I hav 13 MBPRO 2010 2.4 after water damage.
Most damage was done around U7000.
All cleaned etc. now what happens:
1. when battery is in and I connect magsafe - starts on its own
2. No magsafe but battery in - I can start either through power button or using smc bypass.

In both cases macbook gives me 1 beep - no memory, with the ram or without. RAM is 100%. Nothing on the screen

G3 is 3.39 (might my meter is a bit off)

Got some measurment from the U7000:
1 - 0v
2 - 15.9
3 - 3.8v
4 - 0
6 - 3.35
7 - 0
8 - 2
9 - 0.87
10 - 3.3
11 - 3.3
12 3.4
14 - 2
16 - 5
18 - 12.5
20 - 5
21 - 0.5
23 - 2.3
24 - 16.3
25 17.4
28 - 16.4

1.5v and 0.75v for memory is present, 1v for cpu and 5v for usb is there


Also what I noticed that I dont have 18.5 around U5805? IC was replace along with diode and choker - still no joy.

[rickAC]

Originally Posted by rickAC

Hi,

I have a MBP A1278 13". Evererything is functioning apart from three keys: Left Shift, Left Option and Control. I tried a casing with good working keyboard but it didn't help. The fault is on logic board, possibly SMC reset function since those three keys are used for it.


Anyone have success in repairing this fault?

Can it really be that only I have had this fault on this forum?
Not even you Dadioh and cmdrdata

[mac-n-sauce]

Originally Posted by bosna1973

cmdrdata, thank you for your input.
Can you identify this component in red

It's a capacitor:
C3500
10uf
20%
6.3v
x5r
603

Part of the card reader circuit

[cmdrdata]

Originally Posted by rickAC

Can it really be that only I have had this fault on this forum?
Not even you Dadioh and cmdrdata

here are the two sections you may want to probe around and compare good keyboard/logic board vs bad ones and see if they are different. I've never seen that kind of problem so, yes, you're on new ground(s). good luck.

[mac-n-sauce]

Originally Posted by cmdrdata

here are the two sections you may want to probe around and compare good keyboard/logic board vs bad ones and see if they are different. I've never seen that kind of problem so, yes, you're on new ground(s). good luck.

I have a 2010 13" macbook pro with a white screen. Boots and works externally. Looks like the LVDS connector was replaced. Bad replacement? The screen does not look damaged in any way, cable appears to be good. Tried unplug and reseat-no effect.

Any thoughts

[bosna1973]

Can you help me identify this component in red,on one side there is 16.5but on the other side,0

[mac-n-sauce]

Originally Posted by bosna1973

Can you help me identify this component in red,on one side there is 16.5but on the other side,0

What are the specs on the computer? Never mind. 2011 17" macbook pro i7
Looks like a capacitor, but hard to tell from the photo. I do not have the schematic for the 2011 17" maybe someone else out here does. Probably part of the dc-in magsafe circuit. Thats why its reading 16.5v on one side. Its located next to the fuse(the white one) for that circuit.

[bosna1973]

It is a1286 mc118ll/a

[mac-n-sauce]

Originally Posted by bosna1973

It is a1286 mc118ll/a

That photo has a logic board number for a 2011 17" i7

Either way, that will still be a capacitor. What is the problem with the computer?

[bosna1973]

An if lcd-screen is not functional should there be startup sound ,when I press power button I can hear DVD and hard drive spinnig I can see white light but nothing on the screen and no startup sound I try to remuve ram same no startup sound

[mac-n-sauce]

Originally Posted by bosna1973

An if lcd-screen is not functional should there be startup sound ,when I press power button I can hear DVD and hard drive spinnig I can see white light but nothing on the screen and no startup sound I try to remuve ram same no startup sound

That can be bad video, blown backlight, bad cable for the screen. Can you see anything in the screen if you shine a flashlight?

You should get start up chime if its booting. Does not sound like you are getting a boot.

The computer will try and go through the start up procedure by testing the HD and DVD. If you leave it on and it is booted you will be able to toggle the caps lock on and off. If not then you are not getting through the boot process

[bosna1973]

There is nothing on screen when I use flashlight and backlight fuse is OK and you are right computer dosnot boot there is no light on keyboard.

[Musicsoul78]

Originally Posted by rickAC

Can it really be that only I have had this fault on this forum?
Not even you Dadioh and cmdrdata

try smc reset without the keybaord... keyboard removed

it involves you triping the gehot whilst adding or removing magasafe power (battery must be unplugged)

check the keybaord connector on logic board for debris or replace just to make sure!!!

also try external keybaord??

plus new internal keyboard

----------

MAC N SAUCE

Ok i had the same issue turned out to be cable !!

also had another one wich was the lvds connector on logic board, needed to be replaced.

please try a new screen before removing lvds connector.

----------

I have issue with MB A1278 Unibody logic board refurbished

when plugged dc in to dc-board i get flashing green light.

this giving intermittent shots of power and i do not know where to start.

please help

as i can not take any readings as they are constantly changing

ps

Tried 5 new dc in boards all same issue its defo logic board probably a fuse or capacitor???

[mac-n-sauce]

Originally Posted by bosna1973

There is nothing on screen when I use flashlight and backlight fuse is OK and you are right computer dosnot boot there is no light on keyboard.

So now you have no boot issues. You have to start diagnosing why. You are getting power so the G3HOT sounds ok, Is there liquid damage on this board