SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[Dadioh]

In the hopes of generating some technical sharing on this particular HW issue I am starting up a thread to share the symptoms and potential solution to what appears to be a fairly common failure mode on the Macbook Pro 13" (and possible other unibody Macbooks). I suspect these are usually the result of some trauma or liquid spill that damages some aspect of the SMC control circuit. Please feel free to add your own experiences/symptoms and hopefully we can get close to the HW solution.

The symptoms:
The MBP will appear to be completely dead. No response to power button. No response to standard SMC reset procedure.

Temporary bypass:
With the magsafe disconnected press and hold the power button. While continuing to hold the power button plug in the magsafe connector. Continue to hold down the power button for 5 to 10 seconds. Release the power button and wait a couple of seconds. Now press and release power button. PRESTO! The Macbook chimes and starts up but with fan on high speed. Boots up into OSX but with a few caveats which I list below:

Fan runs on high speed.
iStat menus can not sense either temperature or fan speed so access to those sensors is not there. Probably why the fans run on high.
No voltages or power displayed by iStat
"About this Mac" can not see the battery even though it is plugged in.
Does not charge the battery.
Everything else seems to work (Airport, USB, iSight, DVD, Disk)



Taken from the Apple support page about resetting the SMC suggests all of these symptoms are related to non-communication with the SMC. Not sure at the moment why the plugging in of the magsafe while holding the power allows the system to boot. Maybe bypasses some sort of SMC check?


The System Management Controller (SMC) is responsible for many low-level functions on Intel-based Macs. These functions include:

Responding to presses of the power button
Responding to display lid opening and closing on portable Macs
Battery management
Thermal management
The SMS (Sudden Motion Sensor)
Ambient light sensing
Keyboard backlighting
Status Indicator Light (SIL) management
Battery status indicator lights
Selecting an external (instead of internal) video source for some iMac displays

 

[Dadioh]

Another piece of information. If you use this same procedure on a healthy Macbook then it also will boot into this mode with fans on high and not reading the SMC sensors even though it is a fully functioning SMC circuit on a good Macbook. This tells me that this procedure is telling the system to go ahead and boot without relying on the SMC.

 

[macrepair]

Have found on faulty boards that will only turn on with SMC bypass procedure that there is initially no power being supplied to the SMC flashrom. Power is only supplied to flashrom after running the temporary bypass procedure, and this enables you to now turn board on/off as normal until DC power is removed, although there is limited functionality as described in Dadioh's post above.

With a fully functional board there is power on the flashrom the moment DC power is supplied.

Hope this helps with sourcing the faulty component..

 

[Dadioh]

Have found on faulty boards that will only turn on with SMC bypass procedure that there is initially no power being supplied to the SMC flashrom. Power is only supplied to flashrom after running the temporary bypass procedure, and this enables you to now turn board on/off as normal until DC power is removed, although there is limited functionality as described in Dadioh's post above.

With a fully functional board there is power on the flashrom the moment DC power is supplied.

Hope this helps with sourcing the faulty component..

Thanks for the info. I suspect that the symptom is common for a broad range of faults. Anything that prevents the SMC from initializing would lead to the symptom of no boot. The SMC bypass just allows you to get one step ahead and troubleshoot the rest of the board.

I have good news and bad news. The good news (for me) is that I managed to fix my sample board by cleaning off some corrosion near the SMC on the back of the board (this was a liquid spill Macbook that I picked up off eBay). The bad news is that means I can't troubleshoot further on this particular issue until I get another board with these symptoms.

By the way, there is a quick checkpoint to tell you if the board has any chance at all. The power rail "G3Hot" gives 3.425V to the SMC and other logic prior to the rest of the rails coming up at startup. If this power rail is dead then the board is dead. A quick way to see if you have G3Hot is to check the 2 pads near the hard drive connector that allow you to turn on the board without the keyboard button. One side of those pins is G3Hot. If you measure 3.4V then you are one step closer to a live board.

 

[macrepair]

Thanks for the info. I suspect that the symptom is common for a broad range of faults. Anything that prevents the SMC from initializing would lead to the symptom of no boot. The SMC bypass just allows you to get one step ahead and troubleshoot the rest of the board.

I have good news and bad news. The good news (for me) is that I managed to fix my sample board by cleaning off some corrosion near the SMC on the back of the board (this was a liquid spill Macbook that I picked up off eBay). The bad news is that means I can't troubleshoot further on this particular issue until I get another board with these symptoms.

By the way, there is a quick checkpoint to tell you if the board has any chance at all. The power rail "G3Hot" gives 3.425V to the SMC and other logic prior to the rest of the rails coming up at startup. If this power rail is dead then the board is dead. A quick way to see if you have G3Hot is to check the 2 pads near the hard drive connector that allow you to turn on the board without the keyboard button. One side of those pins is G3Hot. If you measure 3.4V then you are one step closer to a live board.

That's great to hear you managed to repair this! I have had a few boards as well that started working after cleaning corrosion. Others have worked for a bit but then failed again!

Can you possibly attach a photo showing the power rail "G3Hot" and pads were this can be tested and alternate way to turn on the board? I have previously done this by connecting pins 5 & 29 on the keyboard connector but the way you mention does seem like an easier option..

 

[Dadioh]

That's great to hear you managed to repair this! I have had a few boards as well that started working after cleaning corrosion. Others have worked for a bit but then failed again!

Can you possibly attach a photo showing the power rail "G3Hot" and pads were this can be tested and alternate way to turn on the board? I have previously done this by connecting pins 5 & 29 on the keyboard connector but the way you mention does seem like an easier option..

Here you go.

 

[chrisgear]

MB 13" uniBody - A1278 - No Power

Hi there Guys

Been reading your posts. I have a MB 13 A1278 that does not switch on.
the LED on the Magsafe does not come on. (all though now and then it turns green)
I have tested G3 hot and the voltage is correct.

The machine did boot when the battery still had power. I unfortunatly do not have another machine with the same battery to test if it is still working.
It is not the magsafe board as I have tried another.
I suspect the fault lies in the initial power circuits before it hits the charging circuit.
I've been shooting in the dark a little as I have no schematics for this board and the problem does not seem to all that common.
Any ideas and tips would be helpfull

Thanks in Advance

Chris

 

[Dadioh]

Chris. That is the non pro unibody 2008? I can help you troubleshoot. Send me a pm. You don't seem to have pm enabled on your account.

 

[chrisgear]

A small amount of progress

Chris. That is the non pro unibody 2008? I can help you troubleshoot. Send me a pm. You don't seem to have pm enabled on your account.

Hi there Dadioh
Not sure how to PM you. I have enabled what I think is PM on my side.
Yes it is a Non Pro Unibody 2008. 2Ghz machine.
I have successfully booted it now using the technique mentioned earilier in this thread.
Here is a bit of history.
NO water/Liquid Damage.
The machine was working then one day it just stopped charging.
I've stripped the Logic board out, cleaned it dried re-assembled it. checked as many components as I can and done my best to find some kind of problem.

Some times when you connect the magsafe connector the LED shines green and then slowly starts to fade. ( I thought this might indicated a faulty Capacitor but it is two random )
After I managed to boot the unit I shut it down completely removed the battery and then re-inserted the battery. reconnected the magsafe and this time it went orange straight away. after approximately 60 secs the led started to fade until it was completely out.

I do have a possible theory surrounding the smc firmware. This machine has been on my desk for nearly a year and was condemned more than a year ago.
So I think it is possible that the the failure could have coincided with the smc firmware update and may there may have been a bad flash.
I'm going to see tomorrow if I can reflash the smc firmware and see if this helps.

let me know if you think I may be barking up the wrong tree.

Thanks

Chris

 

[macrepair]

Here you go.

Thank you!

 

[Dadioh]

Hi there Dadioh
Not sure how to PM you. I have enabled what I think is PM on my side.
Yes it is a Non Pro Unibody 2008. 2Ghz machine.
I have successfully booted it now using the technique mentioned earilier in this thread.
Here is a bit of history.
NO water/Liquid Damage.
The machine was working then one day it just stopped charging.
I've stripped the Logic board out, cleaned it dried re-assembled it. checked as many components as I can and done my best to find some kind of problem.

Some times when you connect the magsafe connector the LED shines green and then slowly starts to fade. ( I thought this might indicated a faulty Capacitor but it is two random )
After I managed to boot the unit I shut it down completely removed the battery and then re-inserted the battery. reconnected the magsafe and this time it went orange straight away. after approximately 60 secs the led started to fade until it was completely out.

I do have a possible theory surrounding the smc firmware. This machine has been on my desk for nearly a year and was condemned more than a year ago.
So I think it is possible that the the failure could have coincided with the smc firmware update and may there may have been a bad flash.
I'm going to see tomorrow if I can reflash the smc firmware and see if this helps.

let me know if you think I may be barking up the wrong tree.

Thanks

Chris

Dumb question but have you tried a different charger? Different battery?

 

[ABCellars]

In the hopes of generating some technical sharing on this particular HW issue I am starting up a thread to share the symptoms and potential solution to what appears to be a fairly common failure mode on the Macbook Pro 13" (and possible other unibody Macbooks). I suspect these are usually the result of some trauma or liquid spill that damages some aspect of the SMC control circuit. Please feel free to add your own experiences/symptoms and hopefully we can get close to the HW solution.

The symptoms:
The MBP will appear to be completely dead. No response to power button. No response to standard SMC reset procedure.

Temporary bypass:
With the magsafe disconnected press and hold the power button. While continuing to hold the power button plug in the magsafe connector. Continue to hold down the power button for 5 to 10 seconds. Release the power button and wait a couple of seconds. Now press and release power button. PRESTO! The Macbook chimes and starts up but with fan on high speed. Boots up into OSX but with a few caveats which I list below:

Fan runs on high speed.
iStat menus can not sense either temperature or fan speed so access to those sensors is not there. Probably why the fans run on high.
No voltages or power displayed by iStat
"About this Mac" can not see the battery even though it is plugged in.
Does not charge the battery.
Everything else seems to work (Airport, USB, iSight, DVD, Disk)



Taken from the Apple support page about resetting the SMC suggests all of these symptoms are related to non-communication with the SMC. Not sure at the moment why the plugging in of the magsafe while holding the power allows the system to boot. Maybe bypasses some sort of SMC check?


The System Management Controller (SMC) is responsible for many low-level functions on Intel-based Macs. These functions include:

Responding to presses of the power button
Responding to display lid opening and closing on portable Macs
Battery management
Thermal management
The SMS (Sudden Motion Sensor)
Ambient light sensing
Keyboard backlighting
Status Indicator Light (SIL) management
Battery status indicator lights
Selecting an external (instead of internal) video source for some iMac displays

I hope me adding here is not considered rude and no offense is taken. I have read this thread with interest and thought I might be able to add a small tid bit to help the great minds working on this problem sift out more of what is happening. I don't believe this is a bypass of the SMC, rather it has been put in a debugging mode. You can still monitor battery charging with CoconutBattery. I believe the SMC is what reports this.

 

[Dadioh]

I hope me adding here is not considered rude and no offense is taken. I have read this thread with interest and thought I might be able to add a small tid bit to help the great minds working on this problem sift out more of what is happening. I don't believe this is a bypass of the SMC, rather it has been put in a debugging mode. You can still monitor battery charging with CoconutBattery. I believe the SMC is what reports this.

Actually that is the point of the thread. Not rude in any way shape or form.

Interesting. So coconut battery reports charging which I "think" is reported by SMC. There is an I2C link from the battery charging device to the SMC and I assume that the SMC summarizes everything and reports to the system.

Battery charging is one of the things it reports but it would be interesting to see if any other program can read information like system temperatures and voltages. I know iStat menus does not and I assumed that therefore the SMC was not reporting those.

Debugging mode may be a better description. When I said "bypass" I just meant that the SMC would not need to pass all of it's system checks before allowing the system to boot.

 

[chrisgear]

Macbook 13" smc issue - Update

Hi there Guys

I now have 2 x 13" with the same problem.
one is the macbook 13" unibody 2008
and the other is a Macbook Pro 13" 2010

the Newer of the 2 is my wifes 13" which she spilt coffee onto.
Fortunately it's battery was fully charged and after cleaning the board and whatever coffee was in the machine it booted again off the battery.
Unfortunately when you connect the charger ( I have several and I tried them all) the green/Amber Light does not come on.
The smc does report that the macbook is connected to power and will then run off the power. It does this because it cannot detect what type of charger is connected (65w or 85w). This is standard behavior and it is designed for use with the airline charger that only provides enough power to run and not too charge. The part of the charger that tells the mac what it is seems to be in the magsafe connector itself.
So what I can only assume is that there is a problem with the sense circuit.
If not that then the connection between the smc and the sense circuit.

Going to start poking around the smc to see what I find (F2117LP)

 

[Dadioh]

Hi there Guys

I now have 2 x 13" with the same problem.
one is the macbook 13" unibody 2008
and the other is a Macbook Pro 13" 2010

the Newer of the 2 is my wifes 13" which she spilt coffee onto.
Fortunately it's battery was fully charged and after cleaning the board and whatever coffee was in the machine it booted again off the battery.
Unfortunately when you connect the charger ( I have several and I tried them all) the green/Amber Light does not come on.
The smc does report that the macbook is connected to power and will then run off the power. It does this because it cannot detect what type of charger is connected (65w or 85w). This is standard behavior and it is designed for use with the airline charger that only provides enough power to run and not too charge. The part of the charger that tells the mac what it is seems to be in the magsafe connector itself.
So what I can only assume is that there is a problem with the sense circuit.
If not that then the connection between the smc and the sense circuit.

Going to start poking around the smc to see what I find (F2117LP)

The charger and the power charging circuit in the Macbook communicate to each other through the 5th wire of the Magsafe connector. The charging circuit is controlled by an Intersil part with restricted access to datasheet.

http://www.intersil.com/products/deviceinfo.asp?pn=ISL6258A

However, this device does communicate with the SMC and the SMC also communicates with the Magsafe. So I would guess that when you plug in the charger it brings up the G3Hot rail (if there is a battery installed then G3Hot is already on) which then brings up the SMC. The SMC then communicates with the Magsafe to determine what it is. If the SMC is happy then it tells the Magsafe to provide full current (before that it is only providing a trickle). The battery charge circuit (ISL6258) then communicates with the battery and determines how much charge current to provide.

So I think it is 4 devices devices handshaking together to run the charging process. The Magsafe controller, the SMC, the Battery, and the Battery Charging Circuit. If any of those is damaged you will probably not be able to charge.

 

[chrisgear]

Got the 2008 unibody working sort of

Ok - Just jotting this down now - don't have the Circuit Diags infront of me at the moment. will check component numbers and post some photo's once I can get to a decent camera.

What happened is this. I was trying to measure the drain of the small mosfet chip which feeds the overvoltage sense circuit to see if it was operating.
I accidentally shorted it and killed the mosfet. The mosfet blew closed circuit and is now feeding the overvoltage circuit constantly.
After the little spark the magsafe's light came on and stayed on.

My new problem is that even when the charger is unplugged the smc thinks a charger is plugged in even though it cannot read it.

I suspect that the original problem may have been that the ground side of the dual mosfet chip that enables the voltage divider that then enables the power side of the mosfet may have been blown open circuit.

Al youl should really need to do is short the source to the drain of that ground side to enable the voltage divider thus enabling the power side of the dual mosfet.

the overvoltage circuit will then enable, test the voltage and enable a connection between the magsafe and the smc via sysonewire though the bilateral switch.

I might be wrong but that is how I understand the circuit.

I am 90% sure that the problem lies in the sense circuit just after the magsafe.

Just a not on magsafe chargers.

the bit that stores the information lives in the magsafe connector.
The Powerbrick senses the load it is connected to and ramps up the voltage if the load is correct.
If you cut the magsafe connector off and use a standard PSU that supplies 16.5v you will find that the light stays on when you unplug it from the mac.
this is because when you unplug a magsafe that is connected to a apple charger the charger drops it's voltage.

 

[Martin81a]

SMC Located

Its the F2117LP chip

 

[Kharlitro]

HI, i'm new in this forum and i have a question:

I've just bought a macbook pro (mid2010, 2.4ghz) damaged by liquid (while turned off, but charging).
Now the mb works fine but it doesn't charge the battery anymore.
I've never tried resetting the smc and right now I'm not able to do it.
A tech said the damage is located on the DC-in board (but without opening it), no one here never thought about this scenario, could you tell me why?


is this a dumb question??

 

[Dadioh]

HI, i'm new in this forum and i have a question:

I've just bought a macbook pro (mid2010, 2.4ghz) damaged by liquid (while turned off, but charging).
Now the mb works fine but it doesn't charge the battery anymore.
I've never tried resetting the smc and right now I'm not able to do it.
A tech said the damage is located on the DC-in board (but without opening it), no one here never thought about this scenario, could you tell me why?


is this a dumb question??

There is no such thing as a dumb question but there are a lot of inquisitive idiots

Kidding of course. No, that is a great question. There is no way for the tech to know if it is the DC in board without opening the Macbook and testing a few points. It is possible that it is the DC board but the way you diagnose this is to see if it is passing through the 18.5V to the logic board. I usually check the input to the inrush FETS to do this or the other way is to check if the white fuse down near the battery connection has 12.5V on it.

There are a bunch of possible reasons why the Macbook won't charge a battery. The charging is controlled by a charging device ISL6258A. If that device is bad or any of the circuitry around it then the battery won't charge. Also, if there is an SMC issue then the SMC can tell the charger not to charge.

I haven't worked on a 2010 model yet but I suspect the charging circuit is the same or similar. Try the SMC reset and, if that doesn't work, report back and I can give you a few points to measure to try and determine what is happening. Do you have some very fine tip probes for your multimeter? Some of the test points may be very tiny and regular test probes will not do.

Good Luck

 

[Kharlitro]

There is no such thing as a dumb question but there are a lot of inquisitive idiots

Kidding of course. No, that is a great question. There is no way for the tech to know if it is the DC in board without opening the Macbook and testing a few points. It is possible that it is the DC board but the way you diagnose this is to see if it is passing through the 18.5V to the logic board. I usually check the input to the inrush FETS to do this or the other way is to check if the white fuse down near the battery connection has 12.5V on it.

There are a bunch of possible reasons why the Macbook won't charge a battery. The charging is controlled by a charging device ISL6258A. If that device is bad or any of the circuitry around it then the battery won't charge. Also, if there is an SMC issue then the SMC can tell the charger not to charge.

I haven't worked on a 2010 model yet but I suspect the charging circuit is the same or similar. Try the SMC reset and, if that doesn't work, report back and I can give you a few points to measure to try and determine what is happening. Do you have some very fine tip probes for your multimeter? Some of the test points may be very tiny and regular test probes will not do.

Good Luck

thanks, now i'm far from my mbp, next week i'll try.

I just called the old owner of the macbook, new info:
The tech from usb runs a minimal software like DOS, and appeared a red string whit something like: BAD CHARGE CONNECTION, so tech said it is a problem of the DC-in, he also observed a large oxydation on original HDD logic (dead and substituded).
The led on Magsafe doesn't blink, but it works on different macbook.

other technicians, contacted through email, told him that the problem would easily be fixed with an ultrasounds washing of the card.

Can i believe this "tech"?

 

[malana]

hello and sorry for the interruption!
I just baked my logic board (mbp early 2008), because it wouldn't start anymore. Now it works - but before the baking, in the dark hours of despair I tried out the SMC Bypass. I found it on some German page I can't find anymore - but I remember the sentence "for some users, this (= the fans at full speed) is not reversible".
Now I've got a working MBP, but the fans won't stop anymore. smc fancontrol doesn't do a thing, numerous conventional smc resets neither.

So what exactly is the name for this procedure? So I can search the web how to have a fully working computer anymore? Or how could I disable it? Surely, there must be a way?

istat is showing all sensors, so it isn't very likely that one is wrecked and causes the fans to act like this.

Any hint will do! Thanks!

 

[Kharlitro]

Hi all,

I have finally been able to reset the SMC, it doesn't work.

So i have taken apart the logic board to see it.

I have uploaded some photos of the card, where the oxidation is more visible and marked:

http://img834.imageshack.us/slideshow/webplayer.php?id=dsc07888t.jpg
Can any of you tell me how to clean my logic board?

@Dadioh, please can you tell me where the Smc is located and where are the few points in which I should take the measurements?

Many thanks

 

[Dadioh]

Hi all,


Can any of you tell me how to clean my logic board?

@Dadioh, please can you tell me where the Smc is located and where are the few points in which I should take the measurements?

Many thanks

Get some 99% pure isopropyl alcohol. You should be able to get it at your local pharmacy. Do not use 70% (sometimes called rubbing alcohol). It has too much water in it. While you are at the pharmacy pick up a new toothbrush. Nothing fancy, just something with medium to firm bristles. Pour a bit of alcohol into a container and then dip the toothbrush in. Apply liberally to the spot you are cleaning and scrub in all directions, back and forth, circular, etc... You can scrub fairly aggressively. Apply more alcohol as necessary by re-dipping the toothbrush. Probably about 60 seconds of scrubbing should do it.

Let it dry about 15-30 minutes and give it a try.

The smc is a square part on the back of the board with part number mentioned earlier in the post. Since your issue is just not charging then it is probably not an smc issue. Try cleaning first and let us know.

 

[cmdrdata]

In the hopes of generating some technical sharing on this particular HW issue I am starting up a thread to share the symptoms and potential solution to what appears to be a fairly common failure mode on the Macbook Pro 13" (and possible other unibody Macbooks). I suspect these are usually the result of some trauma or liquid spill that damages some aspect of the SMC control circuit. Please feel free to add your own experiences/symptoms and hopefully we can get close to the HW solution.

The symptoms:
The MBP will appear to be completely dead. No response to power button. No response to standard SMC reset procedure.

Temporary bypass:
With the magsafe disconnected press and hold the power button. While continuing to hold the power button plug in the magsafe connector. Continue to hold down the power button for 5 to 10 seconds. Release the power button and wait a couple of seconds. Now press and release power button. PRESTO! The Macbook chimes and starts up but with fan on high speed. Boots up into OSX but with a few caveats which I list below:

Fan runs on high speed.
iStat menus can not sense either temperature or fan speed so access to those sensors is not there. Probably why the fans run on high.
No voltages or power displayed by iStat
"About this Mac" can not see the battery even though it is plugged in.
Does not charge the battery.
Everything else seems to work (Airport, USB, iSight, DVD, Disk)



Taken from the Apple support page about resetting the SMC suggests all of these symptoms are related to non-communication with the SMC. Not sure at the moment why the plugging in of the magsafe while holding the power allows the system to boot. Maybe bypasses some sort of SMC check?


The System Management Controller (SMC) is responsible for many low-level functions on Intel-based Macs. These functions include:

Responding to presses of the power button
Responding to display lid opening and closing on portable Macs
Battery management
Thermal management
The SMS (Sudden Motion Sensor)
Ambient light sensing
Keyboard backlighting
Status Indicator Light (SIL) management
Battery status indicator lights
Selecting an external (instead of internal) video source for some iMac displays

I picked up an MBP (mid 2009 unibody) recently and it is totally dead. I tried the SMC bypass trick, but no response at all. No chime, battery state on the side of the MBP shows no charge remains and no charging is going on. The magsafe adaptter is good (worked on my lat 2008 white MacBook), so the problem is definitely on the MBP. When the magsafe is connected, the orange/green LED on the magsafe plug doesn't even glow. The person that asked me to look into this swore that it has never been exposed to any liquid. Taking the bottom cover apart showed that the inside looked pristine and has never been disassembled. ANy suggestions on what to do next is welcome.

Previously I have had experience with a a liquid damaged MB and cleaning it up and letting it dry thoroughly brought it back to life with th eexception of a bad superdrive. I was lucky then. TIA>

 

[jpeezy]

Hi,

I'm having the same exact issue on a 15" 2010 as cmdrdata, except my magesafe LED is green when plugged in and the battery indicators only work when its plugged in. The computer was working fine at 7AM one morning, it went to sleep and an hour later it wouldn't power back on. I tried the SMC reset as described but it didn't work. I can only assume at this point that the logic board needs to be replaced.

Sadly, its 1 month out of warranty

Thanks