SMC Issue on MBP 13 - Hardware Troubleshooting Guide

Discussion in 'MacBook Pro' started by Dadioh, Mar 21, 2011.

  1. Dadioh thread starter macrumors 65816

    Dadioh

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    #201
    The charging controller on the 13" and 15" unibody model is a ISL6258A part. Not certain about 17" but I would guess it is the same. I think I posted a data sheet link earlier in this thread. That will be your starting point. It is a 28 pin QFN package so 7 solder pads each side. It communicates with the SMC to activate charging and then uses a push-pull FET circuit driving an LC network to generate the charging voltage. There is a current sensing resistor (the green device) that feeds back the charging current information to the 6258. Check those FETs to make sure they haven't shorted and check the components around the ISL6258 to make sure none of them are badly corroded.

    Also, there are 1 or 2 FET that control the inrush current to the battery. Make sure those are not blown.
     
  2. fznuk macrumors newbie

    fznuk

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    #202
    Brilliant... thank you for that :D - top man!

    I will have a look at those circuits as soon as i get chance to open the laptop.

    Its working great on mains, and remembers my setting and updates the time/date via wireless etc... but would still be great if i get it working as an actual laptop again :)
     
  3. jugger18 macrumors member

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    #203
    Do any of these look like the sensing resistor?
     

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  4. Dadioh thread starter macrumors 65816

    Dadioh

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    #204
    No. The sensing resistor is near the battery connector. Your photo is near the magsafe connector. When you open the Macbook and have the battery compartment towards you there is a battery connection in the lower right. Near that connection is a green sensing resistor. I will see if I can post a picture in a minute.
     
  5. jugger18 macrumors member

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    #205
    Oops, must learn to read better. Remember this is on a late 2009 polycarboate unibody. I think the logic is the same although the layout is a bit different. Here is a pic by the battery connector.
     

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  6. Dadioh thread starter macrumors 65816

    Dadioh

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    #206
    Hmmm. Polycarbonate unibody. Never worked on one of those but the schematic should be similar even if the layout seems to be radically different. On the macbook pro 13" 2009 in the attached picture I have highlighted the sense resistor. If yours is not on the top side like this then you probably just want to use the battery connector directly. Should be 3 pins at one end of the connector. Be careful not to slip with your multimeter probe.
     

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  7. jugger18 macrumors member

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    #207
    Ok, i could not find the resistor so i went straight to the battery pads....3 right most give pulsing signal

    ----------

    Hard to tell in your pic but does the resistor have writing on it?
     
  8. BigPines macrumors newbie

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    #208
    Yes, mine says "R010" on it.

    Mike
     
  9. jugger18 macrumors member

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    Jul 23, 2007
    #209
    Current sensing resistor, 12V. Light stays green....I dont think the battery is getting any charge, weather this is a dead battery or battery is fully charged I do not know. What can I check next?
     
  10. cmdrdata macrumors 6502

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    #210
    In the A1278 schematic (MBP unibody), there are TWO current sense resistors. On the source of the input the paired FETs, Q7030) the signals are called CHGR_CSI_P and N (current sense in). This is identified as R7020, with a value of 0.02 Ohms. The battery side is called CHGR_CSO_P and N (current sense out). The resistor is identified as R7050, with a value of 0.01 Ohm. Both are 1 Watt resistors. R7050 is the one that charger IC monitors the charging current to the battery. R7020 provides the input current to the battery as well as current for system operation when the Magsafe is providing the power. I am thinking that if the system works of the Magsafe, then Q7055 that controls the battery /input/output line could be bad.
     
  11. jugger18 macrumors member

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    #211
    The question is how to find them...also my system does not boot off magsafe alone either. It acts dead as a doornail although the g3hot is on from the magsafe light is always green.
     
  12. cmdrdata macrumors 6502

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    #212
    That is also my problem. Dadioh at one time said he has a component layout information, so hopefully he can post that someday. Some Apple components are cryptically numbered. For example, in an earlier post the part number identified as "A7 CH". That part is hard to identify unlike other capacitors that are labeled "33 C88", meaning a 33uF polarized capacitor with perhaps 88°C temperature rating. Dadioh.

    BTW, jugger and bigpines, sorry for my chiming in. you both have somewhat different problems, but I have mixed them all un-intentionally.
     
  13. Dadioh thread starter macrumors 65816

    Dadioh

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    #213
    It is on my "to do" list. I had in mind to take a photo front and back and identify the various components that I know of. I have Macbook Pro 13" and Macbook unibody 13" boards in my collection but from what I have seen the designs are fairly consistent between the aluminum unibody models. The photos I saw of the polycarbonate unibody seem "quite" different from the aluminum layouts. However, there may be enough clues in a marked up photo to allow other people to figure out their own boards.
     
  14. jugger18 macrumors member

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    #214
    Not a problem. The more information the better. And dadioh, i look forward to seeing the board layout photo. also any idea where i can get the 1342's schematic?
     
  15. jugger18 macrumors member

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    #215
    A little update. My board lives!! kind of :( It does not recognize a battery is present (known good battery, fully charged) Any ideas?
     
  16. cmdrdata macrumors 6502

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    #216
    Umh, what does it do? Does the system works on MagSafe power but not on battery?

    The system detects battery presence via two lines (something that is similar to SMC+ and SMC- lines in the battery connector. This is how the system determine how much charge the battery has, how many cycles it has been through, etc. If the SMC detects the battery correctly, it then communicates with the charger IC which in turn manage the charging logic.
     
  17. jugger18 macrumors member

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    #217
    It will power up (magsafe) and boot off my external hard drive with OSX 10.6.3 dvd installer on it. If I then run system profiler it shows no battery present and light is green, never turns orange.
     
  18. Dadioh thread starter macrumors 65816

    Dadioh

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    #218
    If you drain the battery down a bit will the magsafe charge it? e.g. Does the magsafe led glow orange? I suspect it may not if the battery is not recognized as being present.
     
  19. jugger18 macrumors member

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    #219
    It will not charge it if i drain the battery or put in another known good battery with less than half charge.
     
  20. Dadioh thread starter macrumors 65816

    Dadioh

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    #220
    Sounds like you need to focus on the battery charging circuit or the battery data connection then. I had some info about that earlier in this thread I believe.

    As cmdrdata said, the battery has some internal brains that can communicate to the SMC to give info about the battery health, charge levels, serial number, etc... Sounds like that communication path is not working.
     
  21. weluvmacs macrumors newbie

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    Sep 30, 2011
    #221
    MPB also does not recognize battery


    Brand new to the forum, and I, like others, have also been blown away by the great technical information and advice in this forum. I have just resurrected a “latte stained” MBP13 (early 2011). All seems to work (using the magsafe) with exception of the battery not being recognized, so this recent series of posts are of great interest to me!

    Extent of my effort thus far has been cleaning the backside of the logic board, cleaning up keys on keyboard (from the top), reformatting HD (had B-Tree errors) and reloading OSX (10.6.8), and doing the basic SMC/PRAM resets, and running disk utility/applejack, etc….still no battery seen.

    I did get some quality time at the Genius Bar. They ran a series of HW and SW diagnostics on the machine and nothing was flagged. Also had them try a new battery in it, but still not recognized (did not ask them if my existing battery was okay...will do that today). I will be picking it back up today and plan to do some of the fuse and voltage checks described in earlier posts, as well as remove the logic board and clean the other side.

    Wife is anxiously awaiting my next steps, since this will be her machine.
     
  22. cmdrdata macrumors 6502

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    #222
    Using the MBP unibody as an example, the internal battery has a 9-pin connector. Pins 4 and 6 are the SMC bidirectional serial data pins SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA lines. The battery power is gated by FET Q7055. Pins 1/2/3 of this FET is tied together and is the S(source) connected to the charger side, and pin 5 is the D(drain) side, connected to the battery V+. Pin 4 of this FET is the G(gate) driven by the charger IC CHGR_BGATE signal. If the battery has a charge on it, then measuring the FET Drain pin should show that battery voltage, regardless of what pin 4 does. Pins 1/2/3 will show the charging voltage from the magsafe and should be close to the voltage reading at the fuse. (again it is easier said than done as I don't know which one is physically Q7055. If pin 5 is equal to battery voltage, the problem is definitely serial data communication. If pin 5 is 0 volt, then the battery is shutdown/safety mode. It normally should have enabled the V+ output when pin 4 of the 9-pin battery connector is connected to the system board 10KOhm resistor, signal name SYS_DETECT_L.
     
  23. weluvmacs macrumors newbie

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    Sep 30, 2011
    #223
    Battery still not recognized

    I removed the logic board from the MBP13(early 2011) and cleaned the remaining latte residue from both sides (not much was left).

    I also charged the battery using an external power supply (Note: the 10k resistor needed to go between pin 5 and ground on the battery plug) and got it up to about 11.25V.

    Put it all back together and MBP would not boot off the battery, nor would any of the battery status lights illuminate. I did measure 11.25v at the battery connector solder points on the logic board.

    The MBP did boot when the magsafe was connected, and the LED stayed green all the time. Battery status just showed the X with 'no battery available'.

    With the MBP on, I measured voltage at the battery plug connector solder points on the logic board...it showed 11.25v (what the battery was charged to). I removed the battery plug and measured voltage at the connector solder points and it bounced between about 12.25 and 11.6v. Voltage at the nearby logic board fuse was 12.27v.

    I also shut down the MBP and disconnected the magsafe and measured voltage at the battery conector solder points. It was on the order of mv. When I connected the magsafe, voltage went up to about 16v or so and then went down to about 3.5v. (battery was still removed).

    So, whatever should tell the logic board a battery is installed and available is not happening.

    Any advice on next steps would be greatly appreciated, otherwise I will just use it as a desktop machine.
     
  24. cmdrdata, Oct 5, 2011
    Last edited: Oct 5, 2011

    cmdrdata macrumors 6502

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    #224
    This is good. A full charge should be around 12.5v

    It indicated that "Q7055" is able to be controlled by the charger IC and is providing that voltage to the V+ of the battery terminals (pins 1/2/3). I am wondering if you leave the battery connected and magsafe plugged in if the battery will actually charge to full load over time. Worth trying, even though the SMC thinks there is no battery.

    I am not clear on this one. With the magsafe and battery disconnected you should not get any significant voltage at the battery V+ solder pads, so the mv reading is probably normal. When you then connect the magsafe with the battery disconnected, the initial 16.5v is expected until the charger IC got a status of no battery from the SMC (the same SDA/SCL lines) which then drops the Q7055 gate signal, thus the 3.5v (or lower) measured.

    With power off, check continuity for the SCL and SDA lines between the battery (connector pins 4 and 6) to the SMC IC (U6900, IC p/n H8S2117) and the charger IC (U7000, IC p/n ISL6258A). The bad news is that the SMC is a ball-grid array chip and the pins are probably not reachable/visible. The schematic says SCL and SDA are SMC pins K7 and K8, respectively.

    I'd also try a KNOWN good battery (borrow from someone you know, or get one from eBay). I bought a new, China made one for under $50.
     
  25. weluvmacs macrumors newbie

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    Sep 30, 2011
    #225
    As far as I am willing to go for now.

    cmdrdata....thanks for the advice and information.

    A new battery was tested at an Apple Service center in the MPB13 and it did not make a difference...still was not recognized.

    I left the current battery installed in the MBP for several hours and measured voltage at the solder points and never saw it change at all (meter read to hundredths of volt)....tried it with the MBP shutdown and booted.

    I did externally charge the battery to 12.2v and installed it with the unit shutdown and magsafe disconnected. I could see the 12.2v at the solder points and both sides of the main fuse near the battery connector, but it would not boot off the battery. And could get any of the battery status indicator lights to come on when pushing the button.

    Located a 2117 chip towards top middle of logic board (far way from the battery connector), but in order to do any continuity checking, I would need to remove the logic board ...not in a position to do that again right now.

    Also could not find a 6258A chip anywhere...maybe on other side of logic board? This is a early 2011 MBP13 and does not look like the logic board photos I've seen posted. I should have taken a picture of the logic board (both sides) when I had it out, but simply did not think of it.

    So, I will use it as a desktop unit for now....I was going to get a new mac mini, but this is much nicer with the built in superdrive.
     

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