Macbook Pro 2010 Not Charging

[platinumsteel]

Hi guys i have an A1278 Macbook Pro 2010 820-2879 that doesn't charge the battery.It can run of a battery.I tried almost everything i know. But PPBUS_G3H just keeps reading 12.21V
Things i tried are as follows: I have another identical Board that gives 12.56v on PPBUS_G3H only thing is it has a bad GPU it seems. So i took most of the parts from it and slapped it onto this good board am working on presently... but it's PPBUS_G3H stays at 12.21v. Have 3x known good batteries. I swapped the SMC.I also swapped the ISL.Tried 2 ''new'' ISL on it.I swapped Q7030 and Q7035 at the same time i tried the new ISL's.Changed R7051 R7052,C7025,R7005,R5087
PPBUS_G3H = 12.21v
SMC_Reset_L = 3.3V
R5280 + R5281 SMBUS_SMC_BSA_SDA and SMC_BSA_SDA_SCL are both 3.4V
on the ISL
R7021 = 12 ohms
R7022 =12 ohms
R7051= 4.5 ohms think my multimeter can't go so low. When i touch my probes i get 2.3 ohms. So if i subtract that from the readings it will be good. So both R7051 and R7052 may be good.
R7052= 2.4 ohms
Pin 2= 16.2v
Pin 3= 3.9v
Pin 18= 12.2v
Pin 17= 12.2v
Pin 14= 3.193v
Pin 23 = 12.22v
Pin 24 = 12.56v

Checked all the resistors around the ISL. They all read ok.Really don't know where else to check for any abnormal voltages or resistances. Unless maybe the SMC is still bad which i doubt cause i took it from the working board.And i did a very good reball job as i have the tools to do it.
Hoping you guys can help.This is not a customer machine it's my spare board just wanted to solve it so that i can build my skill level. thanks.

[mon2]

Hi.

1) Is the battery detected by the logic board ? Does the OS show the charge level of the battery ?

2) With a battery installed and adapter connected, what is the voltage of the following points ?

PPVBAT_G3H_CONN
PPVBAT_G3H_CHGR_REG
SYS_DETECT_L (pin # 5 on J6950 - battery connector)

3) Next, remove all power / no battery. Meter in lowest resistance mode.

a) Measure the resistance from PPVBAT_G3H_CHGR_REG -> pin # 18 of U7000. Try to measure at the IC to confirm the trace between these 2 points is present. R7051 is in series and that is ok.

Resistance reading ?

b) repeat the test but with PPVBAT_G3H_CHGR_R -> pin # 17 of U7000.

Resistance reading ?

[platinumsteel]

PPVBAT_G3H_CONN = 12.22v
PPVBAT_G3H_CHGR_REG= 12.24v
SYS_DETECT_L= 0V

PPVBAT_G3H_CHGR_REG -> pin # 18 of U7000 = 4.7 ohms
PPVBAT_G3H_CHGR_R -> pin # 17 of U7000 = 2.5 ohms

PPVBAT_G3H_CHGR_R -> pin # 17 of U7000=2.5 ohms

[mon2]

Was the SMC taken from the same logic board model?

https://youtu.be/83nIYK00uoM

[platinumsteel]

Yes ofcourse it was taken from the identical board my friend. i didn't even make a joke of it because i am scared of doing reballs on smc and if it was a customer board i may not of even touch it .lol And the board i took it from that SMC was good for sure and the board was doing 12.56v . So i find it strange i replaced the SMC and nothing changed still 12.23v . Thanks a lot for the video i will go over those areas he talked about. Maybe i will put back the original smc as a last resort and see how it goes.

[mon2]

I would consider to remain with the donor SMC since you know it was working -> apply flux and reflow the donor SMC on this board. With proper heating, make the BGA device 'dance' to correct any possible joints that are not seated properly underneath the device.

The SMC is the housekeeper that needs to dial up the higher voltage on U7000 so focus on the SMC.

[platinumsteel]

Hi again my friend well i finally gave up today. This board is definitely determined to be a donor board. I reflowed the smc nothing changed. I took it off and put back the smc that it had on it initially. Nothing changed still 12.23v no matter what i do. But thanks for all the help i got some good practice on smc reballing anyway. So will use this board as a donor.I only have 2 more new ISL chips. Really don't want to risk it putting it on the board and it messes it up some how. I already have wasted 2x new ISL on this board already.thx again for the help.

[piernov]

https://badcaps.net/forum/showpost.p...50&postcount=2

2.2.2. Battery not detected
Issue on charging circuit SMBUS.
Check voltage and diode mode to ground on charging circuit SMBUS SDA and SCL lines

[platinumsteel]

Okay thanks for this i had only checked voltage on the SDA and SCL lines but i just checked diode mode and it seems a little off. i compared those lines with a working 2012 board in diode mode

Trouble board:
SMBUS SDA: 0.517V
SMBUS SCL: 0.540V

Good Board:
SMBUS SDA:0.540v
SMBUS SCL: 0.542v

Will try changing one or both resistors or see what else on the line might be causing this and see if anything changes thanks a lot for pointing this out pier.
Will be sure to get back.

[mon2]

Remove D6950 and check the readings again.

[platinumsteel]

Removed and checked diode mode on everything on the line also replaced the caps just in case specifically on the SMBUS_SMC_BSA_SCL and nothing changed keeps staying at 0.517V . I eventually caved in and put in my last ISL. Still was the same.I also removed the D6950 as you mentioned and checked but still same. Then decided to heat up the area of D6950 and put some alcohol and blow some air pressure to get under the battery connector then i saw diode mode went up a bit it went to 0.520v .maybe margin of error and means nothing. Think maybe i must of done something wrong and the SMC got bad as well. That is the only thing left i guess. I am thinking of removing the Bill connector off the board tho. Do i need it really. not really care about the led reading for the battery on this old model anyway.

[mon2]

removing the Bill connector

Sorry - what is that ?

[platinumsteel]

Originally Posted by mon2

Sorry - what is that ?

That is J6955 connector. There is a little led indicator to the side of the older macbook pros that shows how much charge the battery has. It has a connector for the LEDs . connector is right next to R5280 and R5281. The connector is connected to those SMBUS_SMC_BSA_SCL/SDA lines

[mon2]

hi.

1) each of the ISL devices from U7000 can be recirculated - they are QFN packaged devices so all you need to do is apply flux & desoldering braid to remove the excess solder off the bottom side of the IC and then you can use it again on future logic boards. So they are not being wasted.

2) now see the BIL connector - never heard of it before till you mentioned it. I am assuming that it will not be missed. As a FYI, a few years ago, many developers were stuck with an audio processor design (XMOS) where the USB engine would stop working with their custom design. After we reviewed the case(s), the USB engine was a software IP that demanded a certain amount of bandwidth from the XMOS CPU to operate. However, the engineers created their custom design using different parts on their design and missed out on the factory reference design which made use of certain I2C (SMBUS) peripherals. This on top of that they did NOT remove the code that pinged the hardware that was no longer present on the custom design. So the IP would boot, spend xxx clock cycles searching for an I2C (SMBUS) address of a device that was not present -> led to sucking away CPU time -> led to the USB IP breaking with many faults. This caused many audio devices to fail in the field.

So the summary and concern here is that with the BIL board removed - will the host (I2C / SMBUS Master = SMC) miss the presence of this board ? Or will it just search for it and continue on if the board is not present ? TBD...

3) At this time, the logic board works but will not charge the battery ? Does the Windows OS detect the battery ? Does it show the charge level of the battery ?

4) Understand that you have measured ~3v4 on the SMBUS lines used by U7000 but this only confirms that the lines are not stuck and that the local pull-up resistors are present on these SDA & SCL lines. This test does not confirm that the same pair of lines actually reach the SMC hidden balls.

Consider to remove all power -> perform a resistance check from the pull-up on the SDA line and trace it back to the battery connector pin for the same function.

Then repeat for the SCL line. This is a half baked but valid test to confirm there is no trace break between the points being tested. The real test would be to perform this test from the SMC ball (with the SMC device removed) and to the battery connector.

[platinumsteel]

Would you believe that yesterday when i took off the smc i was going to do that same test but something came up and i completely forgot to do it. I doubt i will want to conduct that test and go over the whole reballing process.I am not lucky with using the paste. I want to order the balls and try that method instead for reballing. When i get that then will take off smc and conduct the test.But thanks a lot for mentioning that should of done that from the very start my bad.

[platinumsteel]

Hi guys i ended up deciding to remove the bill connector.And low and behold there was a crater with corrosion i tried scraping off but it seems to be going deeper am not sure. Am not sure if this will definitely be my issue of that drop in diode mode measurement i have especially on the SDA line.
SDA 0.527V
SCL 0.550V
But do u guys think it will make sense if i try to get away from those viers? Like maybe remove the 2x resistors of their pad and run jumpers from the resistor directly to the capacitors to the back of the board . Like move the resistors of those 2 viers and run jumper wires directly to the back of the board so maybe i can bypass what ever short there is if atold there is a slight short?

[mon2]

Hi. Ok, after a stare of the PCB, can see the pattern (I think).

See attached. Does this look correct on the wiring ?

TOP ARROW = SDA pin.

BOTTOM ARROW = SCL pin.

My suggestion:

1) locate some single strand wire that is flexible.

2) place one end of the strand where the connector pad is showing (SDA) -> apply a bit of flux and solder it in place. Cut off a few inches for the other side.

3) repeat with another fresh strand for the SCL pad.

4) Now apply the other side of the SDA wire to the SDA resistor to bypass the broken PCB trace.

5) Repeat to fix the SCL pad with the SCL resistor in the same way.

6) Now, apply the BIL connector ontop of this stack up and solder each connector pad back into place.

So you are creating a sandwich to fix the 2 traces.

These wires can be longer as it is a SLOW I2C (SMBUS) bus and often is 100khz (400khz max) so not a high speed interconnect.

You can exit the wires from the REAR of the BIL connector (ie. to the LEFT side of your picture) and then around the connector to reach the local resistors.