The SCL/SDA lines in normal operation are pulled up to G3HOT voltage of 3.4v by a 1.5K to 2K Ohm resistors and this line will be pulsed by the SMC with a read/write serial code. It is possible that you have short causing the SDA (Serial DAta) line to get loaded and thus not able to send/receive pulse code to/from the battery. Because of hits the SMC doesn't know that the battery is present and thus not enabling charging logic to turn on. The SCL/SDA line is common to the battery, charger IC and SMC (there are several of these pairs). Does the Apple About info Advance menu detect the battery as being present?
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SMC Issue on MBP 13 - Hardware Troubleshooting Guide
- Thread starter Dadioh
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The SCL/SDA lines in normal operation are pulled up to G3HOT voltage of 3.4v by a 1.5K to 2K Ohm resistors and this line will be pulsed by the SMC with a read/write serial code. It is possible that you have short causing the SDA (Serial DAta) line to get loaded and thus not able to send/receive pulse code to/from the battery. Because of hits the SMC doesn't know that the battery is present and thus not enabling charging logic to turn on. The SCL/SDA line is common to the battery, charger IC and SMC (there are several of these pairs). Does the Apple About info Advance menu detect the battery as being present?
Under System Profiler > Power it shows battery installed = no. I was checking more components and comparing the values, i notices that D6950 Pin 1 has only 3.345kOhms, Pin2 has 7.33kOhms Impediance to ground, where working motherboard has 17.68kOhms on pin1 and 17.50kOhms on pin2. You think that TVS Diode Array is damaged and needs to be replaced?
I have a macbook A1181 M42 (820-1189) which doesn't power up. I believe the problem is the charging circuit. I took measurements on a good logic board. I cannot determine where the fault is. If it is U8300 I wouldn't spend time finding the cause.
Can anyone help with this?
Thanks
Can anyone help with this?
Thanks
Do you have 12v at the system fuse F8300? The problem I believe is NOT the charger chip but the signals that are from/to the lower right of the chip (UGATE,LGATE, EN etc.) or other system voltages that are not being generated. Looking back at my schematic, to get the system to power up using magsafe alone, Q8301 and Q8302 has to be in switching mode (thus regulating the raw DC 16.5v to around 12v which then goes thru fuse F8300 and the battery charging FET. You have 0v at the gate of Q8301 and 0v at the gate of Q8302. Thats not allowing the 12v to be generated by the system.
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Hi everyone, I love re reading this thread, its just amazing the amount of information everyone is so kindly sharing.
I have a problem with a Macbook Aluminium 2.00ghz A1286 I presume (non Pro Model)
Basically it was liquid damaged on the LVDS connector cleaned this out and powered up and worked like a charm, powered down and now will not sign a sign if life, however it does receive G3Hot at about 2.2V or so.
http://i50.tinypic.com/f4pwd0.jpg
Also this chip located 0.5cm below the fan is over heating (too hot to touch) hence I remove the MagSafe to try not to entirely fry the chip. I did use IPA to clean up the contacts and reflowed this chip with flux and hot air but still remains unresponsive.
I have a problem with a Macbook Aluminium 2.00ghz A1286 I presume (non Pro Model)
Basically it was liquid damaged on the LVDS connector cleaned this out and powered up and worked like a charm, powered down and now will not sign a sign if life, however it does receive G3Hot at about 2.2V or so.
http://i50.tinypic.com/f4pwd0.jpg
Also this chip located 0.5cm below the fan is over heating (too hot to touch) hence I remove the MagSafe to try not to entirely fry the chip. I did use IPA to clean up the contacts and reflowed this chip with flux and hot air but still remains unresponsive.
Without clearer image I estimated that this chip has 28 pins and could possibly be the Charger IC (Intersil 62xx) type. If it is, the damage may already happened, and thus preventing the power circuitry from functioning. In actuality, there could be a short someplace else causing this chip to overheat and die.
Here is a photo of the chip from a 2010 A1278, hopefully this will help. There is also one of these by just north east of the ram slot on the same side of the board.
I have also attached a photo of the markings on the chip by the fan. They are different then the ones by the battery.
Attachments
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That is Intersil 6259, the Charger IC. Nice picture by the way. How do you get such nice close ups?
Picture on the left is ISL6258 (also ISL6259) U7000. Picture on the right is TPS51125, a dual 5v and 3.3v regulator. In A1278 chassis, this is U7201
The two side by side photos are the same chip. The second(right side) photo was just an angle view to show the print on it.
The next post I did(single photo) was of the ISL6258.
The photos are taken from a usb digital microscope I bought of eBay for $35
Works good, the photos are from about 2.5" above the board. The stand is not the best, but as you can see it works well. Has led light on it as well.
I am not any farther on trying to resurrect my 2010 A1278. I do not understand the schematics enough yet to be able to locate the parts on the board to test them. Still no magsafe light or battery charging and G3HOT reads 1.40v getting 12v down to battery
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I don't recommend testing this on a board as it may inadvertently apply 12v where you don't want, i.e., whatever the D terminal is connected to other parts.
In my previous edited post (I am thinking that your problem is not getting G3HOT), and I don't want to re-has or re-read everything, it will take too much of my time. I listed the components that will send 12v to the LT3470 from the battery. I'd suggest you find a PC that will run the board layout for your MBP and find the respective components to see where the 12v fail to reach the G3HOT input. This thread has morphed so much and I am unable to address all of the questions and my guess is so does Dadioh. We are all learning from each other and that is very good. So I'll continue to try when I have the time for it, but sorry if some of you do not get answered. This is just a hobby for me and for me to share my experience and knowledge.
Here's a cut and paste of that path: BATT (12v) --> Q7055 --> R7050 --> L7030 --> Q7030 --> R7020 --> Q7085 --> G3HOT regulator.
The SDA line showing 1.9V
I'm following up on my previous post here, my battery is not charging - solid green. So far i have discovered that not just pin 6 but on all SDA lines i'm getting 1.9V SMBUS_SMC_BSA_SDA instead of 3.4V
Components below I'm getting only 1.9V
C6959==>D6950==>U7000
So my question is what should I check now? Cmdrdata said that i may have a short somewhere, but where? I checked the R5280 which carries that line, but it properly shows 2k however the Voltage also shows only 1.9V
Anybody can point me which resistor/capacitor to check in this case would be greatly appriciated.
Note: The battery is not being detected inside OSX, it says battery installed = No
I'm following up on my previous post here, my battery is not charging - solid green. So far i have discovered that not just pin 6 but on all SDA lines i'm getting 1.9V SMBUS_SMC_BSA_SDA instead of 3.4V
Components below I'm getting only 1.9V
C6959==>D6950==>U7000
So my question is what should I check now? Cmdrdata said that i may have a short somewhere, but where? I checked the R5280 which carries that line, but it properly shows 2k however the Voltage also shows only 1.9V
Anybody can point me which resistor/capacitor to check in this case would be greatly appriciated.
Note: The battery is not being detected inside OSX, it says battery installed = No
I'm following up on my previous post here, my battery is not charging - solid green. So far i have discovered that not just pin 6 but on all SDA lines i'm getting 1.9V SMBUS_SMC_BSA_SDA instead of 3.4V
Components below I'm getting only 1.9V
C6959==>D6950==>U7000
So my question is what should I check now? Cmdrdata said that i may have a short somewhere, but where? I checked the R5280 which carries that line, but it properly shows 2k however the Voltage also shows only 1.9V
Anybody can point me which resistor/capacitor to check in this case would be greatly appriciated.
Note: The battery is not being detected inside OSX, it says battery installed = No
The Pull-up resistors for SDA/SCL lines are directly connected to G3HOT, so is your G3HOT also 1.9v? See p42 section C3. They are 1K resistors R5280 and R5281. They each should be 1K Ohm
OOPs, major issue here. I was thinking of MBP with internal battery late 2009. The 9-pin connector is wired different than early 2009. So I was WRONG about pin5 being SYS_DETECT. In your system (A1278 Early 2009) pin5 is SDA line and that line should be at 3.4v when idle (not actively sending/receiving signal from the SMC). In your system, if you are powered by magsafe, then disconnect the battery plug that goes to the logic board (a 5-pin connector J6955), do you still measure 1.9v on both SCL and SDA lines? If SCL is 3.4v and SDA stays at 1.9v, then you have to track down the BATT_SDA lines and check all components hanging on the same signal. NOTE that there are several SMC serial busses and the BATT one is the one that is causing your problem.
What is the state of pin 6 of the 9-pin battery connector? Under normal condition it should be TRUE (logic 1). If it is logic zero (0v), the battery is sending a "bad state" signal. Perhaps you have a bad battery and nothing wrong with your system. If this is the case the signal SMC_BS_ALRT_L = 0v tells the SMC not to charge it as a system self protection.
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SDA/SCL lines
Not sure if we refer to the same schematic mine on Pg 42 refers something different (Firewire Port)
I checked both R5280 and R5281 and they both have 2k Ohms like on the schematic (attached screenshot) so i think they should be good. I see these both resistors on page# 52 bottom right
Resistor R5280 gives only 1.9V where R5281 gives 3.4V. On my second screenshot 3GHOT (PP3V42_G3H) is connected to both resistors R5281 and R5280.
Note: Just to be sure we using the same schem here is mine - Apple Macbook Pro A1278 (K90i, 820-2936)
Not sure if we refer to the same schematic mine on Pg 42 refers something different (Firewire Port)
I checked both R5280 and R5281 and they both have 2k Ohms like on the schematic (attached screenshot) so i think they should be good. I see these both resistors on page# 52 bottom right
Resistor R5280 gives only 1.9V where R5281 gives 3.4V. On my second screenshot 3GHOT (PP3V42_G3H) is connected to both resistors R5281 and R5280.
Note: Just to be sure we using the same schem here is mine - Apple Macbook Pro A1278 (K90i, 820-2936)
OK, we have a disconnect. I do not have K90i. Mine is (based on your MBP 13, EARLY 2009 model quotation in your first post) is M97 (820-2327 ,M97)
SDA lines with 1.9V
Attached is my schematic with the power components. Let me know if you find anything on me getting 1.9V instead of 3.4. Thanks
Attached is my schematic with the power components. Let me know if you find anything on me getting 1.9V instead of 3.4. Thanks
Try this:
1. disconnect BIL connector and measure SDA voltage at the BATT connector
IF the voltage goes to 3.4 then you know it has something to do with that
load.
2. disconnect the battery connector and do the same measurement as above.
3. The only other load is the SMC chip, so I don't know what else you can do.
When you said disconnect you mean remove/desolder J6955/J6950 from the board? or there is another way of making temp disconnection? I just want to make sure before I will be socking components out of the board. J6955 is the battery indicator light connector and the other one is the big connector for battery.
What an interesting thread! I've been searching for a solution for my A1261 17'' MBP and came across this thread. I think the LIO board or the logic board fried after a power outage. Actually, I don't have a battery and my dog pulled the Magsafe a couple of times in the past months...
Now, when I plug in the Magsafe, I get a green light (is this a sign that the LIO board is ok?), but when I turn on the MBP, I only see the fans spinning for a sec and ear the HD and the DVD start and shutdown after a sec (but black screen). I tried the SMC reset procedure, but same thing happens. I also tried holding the power button while plugging the Magsafe and it does something different when I press the button again: the fans runs at full power for a sec and then shut down (but the power-on led doesn't turn on anymore). It keeps doing so after each button press until I remove the Magsafe. Then, its back to the previous symptoms. I've also tried to unplug/replug the PRAM battery, but same result.
Now, I removed the LIO board and I wanted to check the voltages (G3HOT and so on), but it seems the architecture of the 820-2274-A is a bit different than the one of the MBP 13''. I don't see any LT3470. The fuses seem ok, I measure 0.2 ohm. Can anyone please tell me which pins to check? Or if I need to check the LIO board at all if my Magsafe led is green?
Now, when I plug in the Magsafe, I get a green light (is this a sign that the LIO board is ok?), but when I turn on the MBP, I only see the fans spinning for a sec and ear the HD and the DVD start and shutdown after a sec (but black screen). I tried the SMC reset procedure, but same thing happens. I also tried holding the power button while plugging the Magsafe and it does something different when I press the button again: the fans runs at full power for a sec and then shut down (but the power-on led doesn't turn on anymore). It keeps doing so after each button press until I remove the Magsafe. Then, its back to the previous symptoms. I've also tried to unplug/replug the PRAM battery, but same result.
Now, I removed the LIO board and I wanted to check the voltages (G3HOT and so on), but it seems the architecture of the 820-2274-A is a bit different than the one of the MBP 13''. I don't see any LT3470. The fuses seem ok, I measure 0.2 ohm. Can anyone please tell me which pins to check? Or if I need to check the LIO board at all if my Magsafe led is green?