Macbook pro 15" 2011 A1286 stuttering and slow

[resistor83]

hi all, I have a problem with my macbook pro 15 inch, late 2011 with SSD, AMD Radeon HD 6770M dedicated video card and Intel HD 3000 integrated card.

I use the computer occasionally at home and a few weeks ago I noticed that the battery was charging very slowly, I changed the power supply with a new original one and the problem remains. I also changed the battery to a compatible one and the problem persists. Now for a few days I have also noticed that the computer after a few minutes from starting it jerks and becomes very slow. However, this problem arises in several ways:

with the battery attached the problem is always from startup, if I try to enter safe mode the mac shuts down at the end of loading

if instead I disconnect the battery, the computer starts, sometimes it doesn't become slow while other times after a few minutes it starts to jerk and become slow.
In safemode for the moment this problem doesn't seem to exist (without battery)

In normal mode, when the machine doesn't lag I tried to do a gpu test and it works fine, so I assume it's not a video card problem

Do you have any suggestions? Thank you

UPDATE: if I do the SMC with the battery connected, the problem disappears for a few seconds or 1\2 minutes and then returns

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Review the battery connector.

On this connector are 2 pins with the SMBUS interface. One is SCL and the other is SDA.

Measure the voltage to ground of each of these pins. Red meter probe to SCL, black meter probe to ground.

What is the measurement?

Repeat for the SDA pin.

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

both oscillate between 3.46v and 3.49v

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Ok.

From Louis' slides:

I fixed it and they say it runs slow

● Running slow is often due to a sensor issue.
● Not slow as in slow hard drive, I mean slow as in the mouse
stutters as it moves across the screen with no activity.
● The SMC likes to sense voltage levels, current usage, and
temperatures from various different parts of the machine.
● If it receives information that is out of whack, it will turn the
machine off, or make it run very slow as a means to protect
itself from damage.

Run ASD to tell you what sensor is failing
● You will have to venture forth onto the internet to find ASD.
● There are different ASD for every model machine from every
year.
● ASD will tell you what sensor is failing, and then it is your job
to check the schematic and see what's going on.

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

ok thanks, i'm downloading.

Do I have to keep the battery connected when I do the test?

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Test it both ways. The laptop is expected to function with the battery.

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

here the tests with battery connected:

EFI mode




OS mode

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

I recovered the boardview and the schematic, I found the area related to the IB0r sensor.
But now I don't understand why the integrated U5420, U5421, C5420, C5421 and R5423 are not physically soldered?

[retrorepair2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Going to follow this, I'm oddly having the same issue.

I will say this though; Windows 10 will report:

"Windows has stopped this device because it has reported problems. (Code 43)"

This tells me it's somehow gfx card related but not presenting itself in the usual way OR insufficient power in general. It may not be related but I'm suspecting GPU issues, even if it isn't looking like it.

It's almost like the whole system has lost about 1/3 of it's power.

I've not checked that region on mine btw but it's likely the boardview file is based on one specific model or is incorrect. If it's not soldered from factory as it seems from that picture, it's not needed for your model.

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

I solved the problem related to the IB0r sensor, there were three resistors to replace.
Now, however, I am left with the problem of very slow battery charging and I made a mistake when checking the voltages on the board.
I probably accidentally touched this capacitor (C7016) with this resistor (R5280) with the test lead.
From that moment the card doesn't turn on anymore and the power supply has a weak green light.

U7000 is very hot. Do you think it should be replaced?

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Yes, U7000 is likely damaged and will have to be replaced.

The magsafe head led is driven by the 3v42 rail on macbooks. Do not have the schematic open but search for it and confirm this power rail. Likely the same on this model.

What is the voltage to ground of this key power rail?

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

3.49v

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

I replaced U7000 and now the green led lights up.
The fans, however, do not turn by connecting the power supply (I mean motherboard only + fan), while before breaking the integrated U7000 they turned by themselves.
It's normal?
Should I try resetting the SMC?

Haven't tried reading the voltages and reassemble the mac yet. I'll give it a try as soon as I get home from work

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

UPDATE: I tried to mount the motherboard and also connect the battery. In this way the green light is weak, the mac turns on anyway because it feels the battery and in the battery logo there is also lightning but it doesn't charge, I can also unplug the cable and the lightning still remains.

What can it be? Did I solder the U7000 badly?

UPDATE 2: I disassembly the motherboard and the green light came back to normal (just motherboard and fans but not spin)

some misuraments near U7000:

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Measure the voltage to ground of the SMBUS lines on the battery connector.

We need to know if they are working properly. They should be ~3v4 each if ok.

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

SMBUS_PCH_CLK 0\0,30v
SMBUS_PCH_DATA 0
SMBUS_PCH_DATA 0
SMBUS_SMC_0_S0_SDA 0
SMBUS_SMC_A_S3_SCL 0,01v
SMBUS_SMC_A_S3_SDA 0,01
SMBUS_SMC_B_S0_SCL 0,02v
SMBUS_SMC_B_S0_SDA 0,02v
SMBUS_SMC_BSA_SCL 2,95/3,45v
SMBUS_SMC_BSA_SDA 3,00/3,45v
SMBUS_SMC_MGMT_SCL 0
SMBUS_SMC_MGMT_SDA 0

[resistor83]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

Measure the voltage to ground of the SMBUS lines on the battery connector.

We need to know if they are working properly. They should be ~3v4 each if ok.

I repeat the measurements on the connector:

SMBUS_SMC_BSA_SCL 3,31 \ 3,49v

SMBUS_SMC_BSA_SDA 3,33 \ 3,49v

[mon2]

Re: Macbook pro 15" 2011 A1286 stuttering and slow

SMBUS_SMC_0_S0_SDA 0
SMBUS_SMC_A_S3_SCL 0,01v
SMBUS_SMC_A_S3_SDA 0,01
SMBUS_SMC_B_S0_SCL 0,02v
SMBUS_SMC_B_S0_SDA 0,02v

Each is the wrong voltage. Confirm that there are local pull-up resistors on each pin. Then measure the voltage to ground on each side of the pull-up resistor.