SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[mac-n-sauce]

What about with battery removed? Pin 3 seems odd. That is just a simple resistor divider to generate 4V from the 16V coming in. But your pin 1 is at 12V which is also a bit odd. Usually it drifts up to 16V to completely turn off the input FET. Let me know what the readings are without the battery plugged in and just the magsafe.

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That pin 2 CHGR_DCIN is weird. You have 4.7V on pin 3 so that means the resistor divider is getting >16V. But then pin 2 should be getting that same 16V. Check R7005 the 20ohm resistor near pin 2. It may have gone open circuit. Measure resistance with all power removed.

Pin 1/2 16.5v
Pin 3 24.7mv
pin 14 0v
Pin 19/20 5v
everything else basically 0v or really small mv reading

 

[Dadioh]

Pin 1/2 16.5v
Pin 3 24.7mv
pin 14 0v
Pin 19/20 5v
everything else basically 0v or really small mv reading

Well you have 16V coming in on pin 2 but not getting anything on pin 3. Sounds like there is something wrong with the resistor divider. Check R7010 and R7011 near pin 3. Either R7010 is open circuit or R7011 is short circuit. (Or U7000 has pin 3 internally shorted to ground).

 

[mac-n-sauce]

Well you have 16V coming in on pin 2 but not getting anything on pin 3. Sounds like there is something wrong with the resistor divider. Check R7010 and R7011 near pin 3. Either R7010 is open circuit or R7011 is short circuit. (Or U7000 has pin 3 internally shorted to ground).

R7010 is 29.7k good
R7011 is 45 ohm instead of 9.31K (this means its short circuit right?) If it was way low does that mean open?
Might explain my problem. I guess i will need to replace that one?
I did not remove them to measure, but there was no power on the board.

Thanks again for your help. I have a resistor on another board I will replace it with. Do you just solder on top or take the bad one off?

 

[Dadioh]

R7010 is 29.7k good
R7011 is 45 ohm instead of 9.31K (this means its short circuit right?) If it was way low does that mean open?
Might explain my problem. I guess i will need to replace that one?
I did not remove them to measure, but there was no power on the board.

Thanks again for your help. I have a resistor on another board I will replace it with. Do you just solder on top or take the bad one off?

There is the problem. At 45ohms it is pulling that voltage down close to zero. You have to remove the old resistor and replace with a new one.

Open circuit means infinity ohms, no current can pass, like an open switch.

Short circuit means zero ohms, no resistance at all.

 

[paolo8721]

Manually charging battery

An update on my MBP battery and system:

I then hooked up a spare PC laptop power supply (output = 16.5 VDC) to the GND and +V of the battery pack and a voltmeter to the same terminals. I immediately saw the voltage rise up to 10.65v and gradually goes up to 11.9v (in about 45 minutes). I then remove the +V supply and trickle charge teh Li-Ion thru a 47Ohm resistor for about 2 hours, and I got to 12.46v. At that point I remove the charging wiring.

this is from - https://forums.macrumors.com/threads/1122338/ post #66

Can someone please clarify this before I go and blow something up? Will be using a 12v, 6amp, computer PSU. Can get a hold of benchtop supply if necessary.

My understanding - I apply a voltage to pin 1 and 9 (of battery connector) and keep an eye on the voltage between pin 5 and 9?

 

[Rpg16]

Check pins 4 and 6 on the battery connector. Those are the i2c communications from the battery to the charger and SMC. With system running they should be 3.4V. If not then you have a problem on that bus and SMC will not recognize battery -> will not start from battery.

Both of the pins have 3.4v and while the system is running, the battery is recognized, charged and it also works on battery.
Also, the 3.4v is always present on those pins, even if the system is not running, but has power, battery or dc. Could it be a problem with some pull-ups in the battery-powered circuit?

 

[rufunky]

That pin 2 CHGR_DCIN is weird. You have 4.7V on pin 3 so that means the resistor divider is getting >16V. But then pin 2 should be getting that same 16V. Check R7005 the 20ohm resistor near pin 2. It may have gone open circuit. Measure resistance with all power removed.

R7005 resistor is only getting a resistance of .02 ( no where near 20ohm ). So this seems to be a "Short circuit" not an "Open circuit" and needs to be replaced, correct?

Is there a way of identifying these components to use from another logic board without board view? I have tons of laptop mainboards laying around that I could use for parts. If not, where is a good place to get component replacements and do I look this up Just by using "R7005"?

 

[mac-n-sauce]

R7005 resistor is only getting a resistance of .02 ( no where near 20ohm ). So this seems to be a "Short circuit" not an "Open circuit" and needs to be replaced, correct?

Is there a way of identifying these components to use from another logic board without board view? I have tons of laptop mainboards laying around that I could use for parts. If not, where is a good place to get component replacements and do I look this up Just by using "R7005"?

are you using a 2010 13"? you can get them from other boards but they have to be the same. did you pull the resistor off to test it? just did that to mine and it turns out to be ok which means something was giving me a false reading.

If you give me the board numbers you have i can probably tell you where its located

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There is the problem. At 45ohms it is pulling that voltage down close to zero. You have to remove the old resistor and replace with a new one.

Open circuit means infinity ohms, no current can pass, like an open switch.

Short circuit means zero ohms, no resistance at all.

took off the resistor and it measures 9.31k(yuk)
wasn't bad. Now I am having a difficult time getting it back on.
Any thoughts?

 

[rufunky]

are you using a 2010 13"? you can get them from other boards but they have to be the same. did you pull the resistor off to test it? just did that to mine and it turns out to be ok which means something was giving me a false reading.

If you give me the board numbers you have i can probably tell you where its located

Yes, mid 2010 13" mbp. Well I have a early 2011 that I can probably get one off of seeing I will most likely replace that whole board because its missing a bunch of resistors ( and god knows what else ) do to someone improperly cleaning it with an ultrasonic cleaner. But I have the board view for this one so I should be able to locate a replacement part if need be. I just want to wait on Dadioh before I start removing and replacing parts.

Now I am having a difficult time getting it back on.
Any thoughts?

This guys technique seems to work well. https://www.youtube.com/watch?v=PU7wLcuqc-I

 

[laflores]

Hi, I have an issue and I would like to know if you can help me. I have an Early 2011 Macbook Pro 15" that had water damage. The laptop was sleeping when it got wet, and the power adapter was connected. I opened it and checked everything, there was just a little bit of water in the bottom part of the case. The laptop works if it's connected to power, but not from the battery.
When I connect the Magsafe charger to the laptop, it turns on by itself, the sleep light turns on for a few moment, then it flashes like 5 times, and then the laptop starts.
The battery status reads "replace now", and System Info says it has voltage (12410 mV) but no charge (0 mAh).
Do you think it's just a matter of replacing the battery, or could it be something more? Thanks.

Just for the record, I went to the service center and they changed the battery. The laptop is working fine now.

 

[rufunky]

Just for the record, I went to the service center and they changed the battery. The laptop is working fine now.

Awesome, you got lucky! Thanks for the update. Its always helpful when people take the time to come back to explain the solution to their problems.

 

[mac-n-sauce]

Yes, mid 2010 13" mbp. Well I have a early 2011 that I can probably get one off of seeing I will most likely replace that whole board because its missing a bunch of resistors ( and god knows what else ) do to someone improperly cleaning it with an ultrasonic cleaner. But I have the board view for this one so I should be able to locate a replacement part if need be. I just want to wait on Dadioh before I start removing and replacing parts.




This guys technique seems to work well. https://www.youtube.com/watch?v=PU7wLcuqc-I

You can get just about anything you need from digikey.com

 

[rufunky]

You can get just about anything you need from digikey.com

Thanks, how would I search for the part? "R7005 resistor" in the digikey search came up empty.

 

[mac-n-sauce]

Thanks, how would I search for the part? "R7005 resistor" in the digikey search came up empty.

look at your schematic: under the R7005 R= resistor surface mount
20=ohms
0402 is the package size
1/16w = power
5% = tolerance

 

[Dadioh]

R7005 resistor is only getting a resistance of .02 ( no where near 20ohm ). So this seems to be a "Short circuit" not an "Open circuit" and needs to be replaced, correct?

Is there a way of identifying these components to use from another logic board without board view? I have tons of laptop mainboards laying around that I could use for parts. If not, where is a good place to get component replacements and do I look this up Just by using "R7005"?

0.02 "could" mean 20ohms if the meter is reporting in kohms. 0.02kohm = 20ohms.

The other issue could be D7005 which is the diode that feeds R7005. Check voltage on pins 1 and 2. They should be 16V. If pin 3 is not 16V then D7005 is bad.

 

[mac-n-sauce]

Dadioh, so my divider resister was not bad. Any thoughts now. I am having a very difficult time resoldering it on due to its location. Can not get the hot air station to get the board to remain hot enough long enough.Any suggestions?

 

[rufunky]

look at your schematic: under the R7005 R= resistor surface mount
20=ohms
0402 is the package size
1/16w = power
5% = tolerance

Thanks, that makes sense now. Using that info in the filter boxes still came up with no results. I'm not even sure I need to replace this yet so not a big deal.

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0.02 "could" mean 20ohms if the meter is reporting in kohms. 0.02kohm = 20ohms.

The other issue could be D7005 which is the diode that feeds R7005. Check voltage on pins 1 and 2. They should be 16V. If pin 3 is not 16V then D7005 is bad.

Yes, my Multimeter is set to 20K should it be set to 20M?

I have 16.9v going into pins 1 and 2 and 16.9v coming out on pin 3. So this looks good.

 

[mac-n-sauce]

Thanks, that makes sense now. Using that info in the filter boxes still came up with no results. I'm not even sure I need to replace this yet so not a big deal.

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Yes, my Multimeter is set to 20K should it be set to 20M?

I have 16.9v going into pins 1 and 2 and 16.9v coming out on pin 3. So this looks good.

I BELIEVE PIN 3 is supposed to be around 4v because of the dividing resistors. Thats the problem I was having

 

[rufunky]

I BELIEVE PIN 3 is supposed to be around 4v because of the dividing resistors. Thats the problem I was having

OK, Dadioh can you verify this? ( God , I wish you could tag people in here..lol )

 

[Dadioh]

Dadioh, so my divider resister was not bad. Any thoughts now. I am having a very difficult time resoldering it on due to its location. Can not get the hot air station to get the board to remain hot enough long enough.Any suggestions?

If the resistor was removed and measured 9.3K but was 45ohm measurement with the resistor installed then the culprit is the charger IC.

I don't use the hot air station to solder 2 pin devices like resistors and caps. I use a soldering iron for those jobs. Clean off the pads and then put a very small bit of solder on one pad. Move one end of the resistor onto the pad and tack it on. Then apply solder to the other end. Finish up by applying more solder to the end that was tacked. It is a delicate process but comes naturally with a bit of practice. Try it with a practice board removing and reapplying components.

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OK, Dadioh can you verify this? ( God , I wish you could tag people in here..lol )

That is correct.

Here is how a resistor divider works. Pin 3 gets it voltage from the two series resistors R7010 (30kohm) and R7011 (9.3kohm). Total resistance is 39.3kohm so 30kohm will drop the voltage by 30kohm/39.3kohm = 0.75. So 16V * 0.75 = 12V. Starting with 16V you lose 12V across R7010 leaving 16V - 12V = 4V.

You should have 4V on pin 3 if you have 16V at the top of R7010 and both resistors are correct. Of course, this assumes that U7000 pin 3 is a high resistance to ground so that it does not affect the resistor divider. If U7000 pin 3 has failed (and is a low resistance to ground) it can affect the divider and you will not get 4V even if both resistors are correct. In this case you must replace U7000.

 

[mac-n-sauce]

If the resistor was removed and measured 9.3K but was 45ohm measurement with the resistor installed then the culprit is the charger IC.

I don't use the hot air station to solder 2 pin devices like resistors and caps. I use a soldering iron for those jobs. Clean off the pads and then put a very small bit of solder on one pad. Move one end of the resistor onto the pad and tack it on. Then apply solder to the other end. Finish up by applying more solder to the end that was tacked. It is a delicate process but comes naturally with a bit of practice. Try it with a practice board removing and reapplying components.

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That is correct.

Here is how a resistor divider works. Pin 3 gets it voltage from the two series resistors R7010 (30kohm) and R7011 (9.3kohm). Total resistance is 39.3kohm so 30kohm will drop the voltage by 30kohm/39.3kohm = 0.75. So 16V * 0.75 = 12V. Starting with 16V you lose 12V across R7010 leaving 16V - 12V = 4V.

You should have 4V on pin 3 if you have 16V at the top of R7010 and both resistors are correct. Of course, this assumes that U7000 pin 3 is a high resistance to ground so that it does not affect the resistor divider. If U7000 pin 3 has failed (and is a low resistance to ground) it can affect the divider and you will not get 4V even if both resistors are correct. In this case you must replace U7000.

so when the 402 package is in the middle of four other 402 packages then how do you get a iron in there?

 

[rufunky]

That is correct.

Here is how a resistor divider works. Pin 3 gets it voltage from the two series resistors R7010 (30kohm) and R7011 (9.3kohm). Total resistance is 39.3kohm so 30kohm will drop the voltage by 30kohm/39.3kohm = 0.75. So 16V * 0.75 = 12V. Starting with 16V you lose 12V across R7010 leaving 16V - 12V = 4V.

You should have 4V on pin 3 if you have 16V at the top of R7010 and both resistors are correct. Of course, this assumes that U7000 pin 3 is a high resistance to ground so that it does not affect the resistor divider. If U7000 pin 3 has failed (and is a low resistance to ground) it can affect the divider and you will not get 4V even if both resistors are correct. In this case you must replace U7000.

Ok, this is getting a little more complex but I believe I understand. I'm getting 16.9v when measuring the right side ( top? ) of R7010 and 4v when measuring the left side ( bottom? ) of R7010.

Are my resistor readings correct seeing they have a K at the end? Can I change my Multimeter to read in ohms if they are not currently?

 

[Dadioh]

so when the 402 package is in the middle of four other 402 packages then how do you get a iron in there?

I use a very fine tip on my metcal soldering iron and solder under a microscope. Sounds like your iron tip is too big if you can't get to a single resistor in a row of them.

 

[rufunky]

Mac-n-sauce if your not using a stereo microscope do yourself a favor and check this one out. I just purchased it and for the budget conscious its awesome! It has a 9" working distance so you have tons of room to position your iron with out bumping into the microscope.

http://www.amazon.com/AmScope-Widef...372887082&sr=8-30&keywords=amscope+microscope

 

[mac-n-sauce]

I use a very fine tip on my metcal soldering iron and solder under a microscope. Sounds like your iron tip is too big if you can't get to a single resistor in a row of them.

Does the tip have a dimension?

I was able to get them on, I removed one in front, then put the inside one on then put the outside one back on.

I am now trying to remove the 28 pin chip. with flux and my hot air station at 400 I can not seem to get it to flow the solder. Any ideas on that.