SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[chigwelldave]

Hi Chigwelldave

So I've checked the C7292 and I have 3.33V at PIN 1. Any idea where the problem is. Thanks Chigwelldave for your time and effort.

EDIT: Also check the Q7220 from Pin 1 to 4 = 0.0v Pin 5= 12.60v and Q7225 from pin 1 to 5 = 0v nothing. C7565 is 0.0v and C7568 is 0.0v nothing. Q7565 pin 5 = 0.0v

Diagram and board view is here https://forums.macrumors.com/posts/14888012/

Regards,
SKRMobiletech

Hi SKRMobiletech,

OK, you have stage5 3V3 so check Q7910 (3V3 S3 switch) pin 4 (3V3 S5) should be 3.3V and pins 1,2,5,6 (3V3 S3) should be 3.3V if it's OK and switched on. Then check your Q7930 (3V3 S0 switch) which should have 3.3V on pin 4 and 3.3V on pins 1,2,5,6 if it's on and OK. These power FETs are on page 69 of the schematic. Looks like there could be a problem with one of the FETs or control signals as you don't have 3V3S0 on U5420 pin 3.

Regards,

Chigwelldave.

 

[SKRMobiletech]

Hi SKRMobiletech,

OK, you have stage5 3V3 so check Q7910 (3V3 S3 switch) pin 4 (3V3 S5) should be 3.3V and pins 1,2,5,6 (3V3 S3) should be 3.3V if it's OK and switched on. Then check your Q7930 (3V3 S0 switch) which should have 3.3V on pin 4 and 3.3V on pins 1,2,5,6 if it's on and OK. These power FETs are on page 69 of the schematic. Looks like there could be a problem with one of the FETs or control signals as you don't have 3V3S0 on U5420 pin 3.

Regards,

Chigwelldave.

Hi Chigwelldave,

Ok, I've just checked the Q7910 Pin 1,2,5 & 6 are 0.0volts and pin3=3.31v, pin4 3.33v. Look like this Q7910 is BAD. What do you think! or it could be the QFN U7201 since this is the power source for the Q7910.

Regards,
SKRMobiletech

 

[chigwelldave]

Hi Chigwelldave,

Ok, I've just checked the Q7910 Pin 1,2,5 & 6 are 0.0volts and pin3=3.31v, pin4 3.33v. Look like this Q7910 is BAD. What do you think!

Regards,
SKRMobiletech

Hi SKRMobiletech,

I would expect a greater voltage difference between pins 3 and 4 to turn the FET on, perhaps look at the P3V3S3S3_EN line (should be around 3.4V), Q7912 and R7910. Also check C7911 is not short (or the FET short between pins 3&4).

Regards,

Chigwelldave.

 

[SKRMobiletech]

Hi SKRMobiletech,

I would expect a greater voltage difference between pins 3 and 4 to turn the FET on, perhaps look at the P3V3S3S3_EN line (should be around 3.4V), Q7912 and R7910. Also check C7911 is not short (or the FET short between pins 3&4).

Regards,

Chigwelldave.

ok Q7912 the P3V3S3S3_EN line is 3.31v and R7910 3.31v C7911 i cannot get any volts reading on it. I test it with capacitors tester and cannot get any value.

thanks
skrmobiletech

 

[etypecie]

A1278 820-3115 b

Hello.
You're doing great job here!
I would like if you could help me too.
I have Macbook A1278 with 820-3115-B motherboard after water damage.
There is no backlight of screen (flashlight trick works) and keyboard. I check voltage :
I2C_BKL_1_SCL 3,3V at R9753
I2C_BKL_1_SDA 3,3V at R9757
LCD_BKLT_PWM 3,3V at R9704
PP3V3_S0_BKL_VDDIO 3,3V at C9711
PPBUS_SW_BKL 12,4V at C9712
PP5V_S0_BKL 5V at C9710 and C9714
PPBUS_S0_LCDBKLT_FUSED 12,4V at F9700 and on out Q9706
PP3V3_S0_LCD 3,3V at R9008 and R9009
PP3V3_LCDVDD_SW 3,3V at L9004
PPVOUT_SW_LCDBKLT 12,4V at C9020
PPBUS_SW_LCDBKLT_PWD 12,4V at R0910 and then 3,06V at R9715
and there it 0V at BKL_ISEN1,..,BKL_ISEN6, so this is mean that U9701 need to be replace?

Albo Magsafe works 1 on 5-10 tries. I have to plug it slowly and then there is green light and it starts (no battery inside).

Please help me with backlight and connector.
Thanks in advance.
PS: Sorry for my english.

 

[chigwelldave]

ok Q7912 the P3V3S3S3_EN line is 3.31v and R7910 3.31v C7911 i cannot get any volts reading on it. I test it with capacitors tester and cannot get any value.

thanks
skrmobiletech

Hi SKRMobiletech,

R7910 pin 1 should be 0v, pin 2 should be between 0V and 2.6V to turn Q7910 on. C7911 is across Q7910 pins 3 & 4 so, according to your earlier readings should be ~3.4V to ground (0V across it). If R7910 pin 1 is not low when P3V3S3S3_EN line is high then it looks like Q7912 is bad.

Regards,

Chigwelldave.

 

[SKRMobiletech]

Hi SKRMobiletech,

R7910 pin 1 should be 0v, pin 2 should be between 0V and 2.6V to turn Q7910 on. C7911 is across Q7910 pins 3 & 4 so, according to your earlier readings should be ~3.4V to ground (0V across it). If R7910 pin 1 is not low when P3V3S3S3_EN line is high then it looks like Q7912 is bad.

Regards,

Chigwelldave.

Ok thanks Chigwelldave I will try oder the parts and I will get back to you one I replace it. Once again I do really appreciate your time with me. Thanks a lot.

Regards,
SKRMobiletech

 

[SKRMobiletech]

Hello
Great forum
Iam working on a water damaged macbook pro 13 2010 A1278 EMC:2351.
The mac charges the battery and G3hot is good. But it wont start Great if someone could help me out where to look.

Ps I think there something wrong with my 5V supply, where can I find this on the PCB ?

Thanks

anybody want to share the board view and schematic diagram for LB EMC:2351
MBP 13 MID 2010. My MBP only start with FAN high speed no video no chime.

Regards,
SKRMobiletech

 

[nicoar10]

anybody want to share the board view and schematic diagram for LB EMC:2351
MBP 13 MID 2010. My MBP only start with FAN high speed no video no chime.

Regards,
SKRMobiletech

Take it from my dropbox

https://www.dropbox.com/sh/g7y3vz361xvvl0n/RrDsOIiZzX

 

[SKRMobiletech]

Take it from my dropbox

https://www.dropbox.com/sh/g7y3vz361xvvl0n/RrDsOIiZzX

Thanks nicoar10.

 

[South657]

Hi Cmdrdata,
I am working on 2011 board with no G3 hot, all looks good until I get to U6990 no volts to L6995 I was thinking of doing the same trick as Chigwelldave, as the fault is open and not a short he has confirmed it works so I will now do that, and let you know how I get on. My eyes are not too good and I shake like Louis Rossmann, and changing U6990 is hard for me so I will get a friend with good eyes and good rework skills to do that, but only if I have a positive result from that trick. Finding the fault and getting chime is the biggest buzz for me.

Regards
South 657

Its been a time since I was last on I had U6990 replaced and now have G3Hot. Good you would think problem solved? Hold on not so fast, OK I have 16v from magsafe bright green light 12v to the battery magsafe only tried the pads and power on no luck, put battery in tried pads and power on no luck. Ok looked at U7000 pin 1=0, 2=16v, 3=4v, 14=3.3v, 19/20 5v, 27/28=16v good. So I moved on to U7200 just touched it very hot turned
all power off. So is it just the chip or other components shorting making it hot? Have run out of time today will look at it again when i have time. Any
one else had this? All ideas would be good and welcome. I have read all this thread and learned so much thank you all.

Cmdrdata did you have any luck with the 09 with no G3hot?

 

[nicoar10]

No News:: NO POWER ON

@CMDRDATA

Hi Boss,

I keep working on this a1278 2010 board that no power on.
3,42v present
charge battery
51125 ok

Some post before you mentioned find ALL_SYS_PWRGD.
i take some measurements.
Anyway i replace this component and no change in the board.
Do you know how to follow this line ALL_SYS ?

Need i measure from PGOOD out each Vcore component ( 51125,MCP,CPU,RAM) .

Thanks!

I keep working in this board, no news

 

[cpufixer]

hi guys, how do I open board view with mac, the above post is for pc...thanks

Edit: I am in need of some parts,:

 

[cpufixer]

hi guys, how do I open board view with mac, the above post is for pc...thanks

Edit: I am in need of some parts,:

This board wants to boot, nothing on screen...power button problems, keyboard needs cleaning, trackpad clicking problems...

 

[chigwelldave]

hi guys, how do I open board view with mac, the above post is for pc...thanks

Edit: I am in need of some parts,:

Hi cpufixer,

The Landrex application runs under Wine in both OS X and Linux.

Regards,

Chigwelldave.

 

[SKRMobiletech]

Hi SKRMobiletech,

R7910 pin 1 should be 0v, pin 2 should be between 0V and 2.6V to turn Q7910 on. C7911 is across Q7910 pins 3 & 4 so, according to your earlier readings should be ~3.4V to ground (0V across it). If R7910 pin 1 is not low when P3V3S3S3_EN line is high then it looks like Q7912 is bad.

Regards,

Chigwelldave.

Hi Chigwelldave, do you know where can I get this parts? I been searching in the internet and cannot find a sources.

Thanks
SKRMobiletech

 

[chigwelldave]

Hi Chigwelldave, do you know where can I get this parts? I been searching in the internet and cannot find a sources.

Thanks
SKRMobiletech

Hi,

Mouser have them in stock under part number 757-SSM6N15FETE85L,F.

Regards,

Chigwelldave.

 

[SKRMobiletech]

Hi,

Mouser have them in stock under part number 757-SSM6N15FETE85L,F.

Regards,

Chigwelldave.

Thanks Chigwelldave i have it order.

 

[soyo]

My 820-2850-A MB cannot power on

My 820-2850-A MB cannot power on.

Conditionwithout battery and without magsafe power board in)

First I checked 51125 Vin and found Vin is shorted to GND first. Then I checked ISL6259 chip. The pin 23 is shorted to GND. What is next to check? PPDCIN_G3H is directly from magsafe dc jack board. But it's not shorted.

 

[South657]

chime

Hi all this one has me stumped k90i 2.4 late 13" non working, cleaned LB
put it back in boots up grate, no chime? smc reset no chime? pram reset no chime? sound on ok plays cd no problem.
My question any one know the origination i.e. the place of the chime SMC?
Help on this would grate thanks and regards to you all

 

[South657]

SMC reset

Hi all this one has me stumped k90i 2.4 late 13" non working, cleaned LB
put it back in boots up grate, no chime? smc reset no chime? pram reset no chime? sound on ok plays cd no problem.
My question any one know the origination i.e. the place of the chime SMC?
Help on this would grate thanks and regards to you all

I Had a look in to this today it could be the old owner has flashed the bios chip
this may not be a bad thing as i found a lot of people do not like the chime LOL

So good out come on this one my 3rd so far still working on another.

When i was reseting SMC it melted the the charger it was smoking and crackling at the wall socket. This was not a genuine apple charger so a warning
to us all use genuine. As I am new to apple I will not make that mistake again.

 

[nicoar10]

A1278 2.4 2010 Working so slow when works from Battery - SOLUTION INSIDE

Hi guys, now i got a just repaired a1278 2010 2.4 board.

i had to fix some connectors and full working now but a new issue appear.

When im working from magsafe and battery connected everything works perfectly but when battery is full charged and remove magsafe system begin to work so slow.

I see same issue in retina 13" ( applestore change mac for warranty)
When genius run test show a amperage sensor issue.

Any idea?

SOLUTION

After run ASD, it´s showed a PBUS bad sensor.
Replace Q5315, now everything works perfectly.

Another fixed board

 

[Rookietowm]

No Icam on Mac Pro 15 I5 2.40ghz

Hello Everybody, I have a Mac pro 15" I5 2.40ghz and the motherboard model is 820-2850A . Everything works except it wont detect the camera, I have swaped good working screens and still no luck, I have also checked around the connector and it looks clean under the microscope. Could you please share some knowledge on where to start looking, measuring voltages or checking IC;s please. Thanks in advance!!!

 

[South657]

Hello Everybody, I have a Mac pro 15" I5 2.40ghz and the motherboard model is 820-2850A . Everything works except it wont detect the camera, I have swaped good working screens and still no luck, I have also checked around the connector and it looks clean under the microscope. Could you please share some knowledge on where to start looking, measuring voltages or checking IC;s please. Thanks in advance!!!

I have just had the same problem, it was in my case the camera did you test
the camera on the good screen first? All so have you done any soft ware downloads? Some times a conflict can stop camera and other hard wear from working

Have a look at C3452 L3408 & L3407 it then looks like it uses USB port?
Test the ports see if they work OK good luck.
south657

 

[Rookietowm]

I have just had the same problem, it was in my case the camera did you test
the camera on the good screen first? All so have you done any soft ware downloads? Some times a conflict can stop camera and other hard wear from working

Have a look at C3452 L3408 & L3407 it then looks like it uses USB port?
Test the ports see if they work OK good luck.
south657

hi! thanks for the quick answer, Im going to look for these components and report back, thanks!!!