SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[triplelucky]

Crawlah

Thats a nice job of cleaning the board. What you need to get now is the “board view” file that matches your schematics. With the board view you can look at a diagram of the board layout and click on the part in question, get its IC part number and also the different signal names at the different chip pins and other points. Then you can reference back and forth between your schematics and your board view. That way you know the names and locations of all the parts on the board as well as their signal names that you will see on your schematics.

Cinarca

The only time Ive seen that behavior ( shutting down without a constant keypress) was with an 09 15 inch. The board on that one was not water damaged but the keyboard had had a spill. Replacing the keyboard fixed it.

 

[Crawlah]

Crawlah

Thats a nice job of cleaning the board. What you need to get now is the “board view” file that matches your schematics. With the board view you can look at a diagram of the board layout and click on the part in question, get its IC part number and also the different signal names at the different chip pins and other points. Then you can reference back and forth between your schematics and your board view. That way you know the names and locations of all the parts on the board as well as their signal names that you will see on your schematics.

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Wow.. I just got my hands on the board view file.

That just opened up a whole new world to me. I can now access the info i was looking for. Many thanks for the help triplelucky! I now have some work to do! =)

I think the R7402 (burned on my logic board) is important i did read somewhere in this thread that a person named Laptech fixed a board with similar faults as mine via just thatone resistor.

 

[Cinarca]

The only time Ive seen that behavior ( shutting down without a constant keypress) was with an 09 15 inch. The board on that one was not water damaged but the keyboard had had a spill. Replacing the keyboard fixed it.

Thanks for your reply, actually I tried to jumpstart it with the keyboard and the trackpad disconnected, it is shutting down either during the boot process or even sooner, not even getting the startup sound.

 

[greekhero]

The easiest part is if there is an issue with main power. Rest is just too difficult to trace (for me). What color light do you get on magsafe when you plug both the battery and magsafe? If you get dim green or no light then you should locate the ISL6258 or ISL6259 and then check the various pin values. Post the voltages on pins: 1,2,3,14 here. The voltages on these often tell if there is a problem with recognizing charger and battery. Since only one can power the board at a time an issue here can result in dim green or no charger light.

Cheers!

Hi, guys !
I'm new to this forum . Sorry for my english in advance, since I'm from Latvia .

I have been folowing this thread for a week or more but since I could not find any answer to my questions I wanted to ask directly .

I have a Mac A1342(820-2877-b) that does not power up via megsafe nor battery. I attached also the schematic of the logic board (hope this helps to get further). I believe that some of other schematics meet this one.

As aleardy mentioned in the previous #: I have 3.38 at the G3H, the battery outputs shows 11.20V (1/2/3 pin) and the megsafe ~ 17.14V .
Where should I look next ?

I appreciate any answer, thank you !

 

[SKRMobiletech]

Macbook Pro 13 MID 2010

I am a newbie here and reads a lot of good stuff to learn.


Anyway, I have a MBP 13" MID 2010 that turn on without video and chime but the fan run at full speed and the sleep light lit solid white no blinking. Is somebody can help me out to start troubleshooting my BAD logic board I would really appreciate it if somebody can point me in the right direction to start with.

Thanks
SKRMobiletech

 

[dellxps15]

here i am again, with another a1278 core duo macbook. after some inspection (no battery indicator, no power on no green magsafe, i found a short on a backlight fuse (only from down position) and fuse ofcourse not working.
tryed replacing isl6529 with another (dunno if working) but still no magsafe green.
i also tryed removing the backlight ic but short is still there. it got water damage, and now all is cleaned. that marked red ring was corroded. now after clean and do some fresh resoldering all connection are clean. if i tesh with multimeter no short from this side, and no short on pin 23 of the backlight ic, but the backlight fuse is shorted in the posizion showed on picture. where i have to focus my attention? (lvds connector is a bit damaged, can be that the problem? don think that because nothing go from a fuse directly to a lvds connector.
where can i find boardview and program to read them ?

any help would be appreciated.


edit: removed lvds ,fuse and the 3 pin mosfet on the right of fuse in picture that should be Q9807 and on pin 1 is shorted, so if i look on the schematic, only 3 possible caouse: 2 resistor and 1 capacimeter, r9808 r9809 and C9802.

 

[chigwelldave]

here i am again, with another a1278 core duo macbook. after some inspection (no battery indicator, no power on no green magsafe, i found a short on a backlight fuse (only from down position) and fuse ofcourse not working.
tryed replacing isl6529 with another (dunno if working) but still no magsafe green.
i also tryed removing the backlight ic but short is still there. it got water damage, and now all is cleaned. that marked red ring was corroded. now after clean and do some fresh resoldering all connection are clean. if i tesh with multimeter no short from this side, and no short on pin 23 of the backlight ic, but the backlight fuse is shorted in the posizion showed on picture. where i have to focus my attention? (lvds connector is a bit damaged, can be that the problem? don think that because nothing go from a fuse directly to a lvds connector.
where can i find boardview and program to read them ?

any help would be appreciated.


edit: removed lvds ,fuse and the 3 pin mosfet on the right of fuse in picture that should be Q9807 and on pin 1 is shorted, so if i look on the schematic, only 3 possible caouse: 2 resistor and 1 capacimeter, r9808 r9809 and C9802.

Hi dellxps15,

What is the logic board type (820-xxxx)? Do you have 3.4v on your G3HOT? You won't get anywhere until your G3HOT is working - no magsafe LED or BIL.

Regards,

Chigwelldave.

 

[dellxps15]

hi, board type is 820-2530. magsafe ligh turn on but very softly..... almost not visible. no 3.42v g3hot. isl6259 pin 3 is 4 volt.

led fuse is shorted.

 

[skuja3]

The easiest part is if there is an issue with main power. Rest is just too difficult to trace (for me). What color light do you get on magsafe when you plug both the battery and magsafe? If you get dim green or no light then you should locate the ISL6258 or ISL6259 and then check the various pin values. Post the voltages on pins: 1,2,3,14 here. The voltages on these often tell if there is a problem with recognizing charger and battery. Since only one can power the board at a time an issue here can result in dim green or no charger light.

Cheers!

Sorry for the delay ..
The measurments are (attachment) . The Megsafe now has a dim light, previously it was solid, looks like i shorted something on the ISL.
Can someone tell what is the component (330) ? I seems burned inside. What does it do ? Where can i found such component ?

Thank you !

 

[chigwelldave]

hi, board type is 820-2530. magsafe ligh turn on but very softly..... almost not visible. no 3.42v g3hot. isl6259 pin 3 is 4 volt.

led fuse is shorted.

Hi dellxps15,

Firstly you'll need your G3Hot working. Check you have 11-17v on C6990, if not check R6905 and D6905. If these are OK then U6990 is probably bad. Also check C6999 is not short.

Regards,

Chigwelldave.

 

[dellxps15]

Hi dellxps15,

Firstly you'll need your G3Hot working. Check you have 11-17v on C6990, if not check R6905 and D6905. If these are OK then U6990 is probably bad. Also check C6999 is not short.

Regards,

Chigwelldave.

hi again, without a board view i dunno where these component are located

edit: u6990 founded and after remove it i have a similar case like this one:

https://forums.macrumors.com/posts/16788790/

i was trying to solder it back, but maybe it's better to take it off, get a replacement and see if i have to do like him, put a wire to jump to a point to point. i have a 0.1mm wire (1/10 of millimeter)


Edit: i've discovered that the shorted fuse is not the backlight fuse (that there is and is a 0402 like reported in schematic), but a 1206 fuse that have not reported on the schematic i have here.
downloaded the schematic for that mainboard and still cant find it....

edit2: after a search on the net, i discovered that this white thing is not a fuse (really strange) but is a capacitor C9796 200PF 5% 100V CERM 1206.
that means capacitors is ok and there is no short here, so i have to focus for g3hot voltage. ill buy a new lt3470

 

[chigwelldave]

hi again, without a board view i dunno where these component are located

edit: u6990 founded and after remove it i have a similar case like this one:

https://forums.macrumors.com/posts/16788790/

i was trying to solder it back, but maybe it's better to take it off, get a replacement and see if i have to do like him, put a wire to jump to a point to point. i have a 0.1mm wire (1/10 of millimeter)


Edit: i've discovered that the shorted fuse is not the backlight fuse (that there is and is a 0402 like reported in schematic), but a 1206 fuse that have not reported on the schematic i have here.
downloaded the schematic for that mainboard and still cant find it....

edit2: after a search on the net, i discovered that this white thing is not a fuse (really strange) but is a capacitor C9796 200PF 5% 100V CERM 1206.
that means capacitors is ok and there is no short here, so i have to focus for g3hot voltage. ill buy a new lt3470

Did you check the other components around U6990? Also, if you lost the pad for pin 7 don't worry - it is a 'no connect'.

Regards,

Chigwelldave.

 

[t0p0ne]

hi again, without a board view i dunno where these component are located

edit: u6990 founded and after remove it i have a similar case like this one:

https://forums.macrumors.com/posts/16788790/

i was trying to solder it back, but maybe it's better to take it off, get a replacement and see if i have to do like him, put a wire to jump to a point to point. i have a 0.1mm wire (1/10 of millimeter)


Edit: i've discovered that the shorted fuse is not the backlight fuse (that there is and is a 0402 like reported in schematic), but a 1206 fuse that have not reported on the schematic i have here.
downloaded the schematic for that mainboard and still cant find it....

edit2: after a search on the net, i discovered that this white thing is not a fuse (really strange) but is a capacitor C9796 200PF 5% 100V CERM 1206.
that means capacitors is ok and there is no short here, so i have to focus for g3hot voltage. ill buy a new lt3470

Here is the boardview for 820-2530 K24 for you and others don't have this should save a copy for yourself.Note: rename .zip to .brd
Also dellxps15, the white component you screenshot isn't the BCKLT fuse, it's the cap C9796, your BCKLT fuse should be north of that, see photo

 

[dellxps15]

Did you check the other components around U6990? Also, if you lost the pad for pin 7 don't worry - it is a 'no connect'.

Regards,

Chigwelldave.

on lt3470 i have volt only on pin 8: 17.8volt .should be ok then and that means lt3470 is bad...

Here is the boardview for 820-2530 K24 for you and others don't have this should save a copy for yourself.Note: rename .zip to .brd
Also dellxps15, the white component you screenshot isn't the BCKLT fuse, it's the cap C9796, your BCKLT fuse should be north of that, see photo

yes founded that it wasnt a fuse, but really strange it's color like the other big fuse. i have founded backlight fuse and is a well known brown with a dot on it.

about no g2hot voltage, as described i have 17volt on pin8. and D6905 HN2D01JEAPE was with all pins black, same for resistor R6905 all with pins black outside the board (maybe oxidation? i have to replace them ? d6905 i see is difficult to find...

tnx you very much for the .brd. do you have also .brd for 820-2567 ?



PS: on your image the quality is so good i can even read all components

 

[dellxps15]

As long as pins 1,2,3 AND 5 are not short on Q7035 then that part is ok. If you look at the diagram in my earlier post you will see that pins 1,2 and 3 are all connected to ground (GND), so what you are measuring is correct.

So, considering the short has now gone from the coil, you can safely say you have found the faulty part, Q7030, well done.

hey, today i replaced the q7035 with one component from another macbook. macbook as before start only with battery and when start make no bong, no display and restart after a bit with fan going to full speed...

g3hot is 3.7v on my multimeter.

with ac i have no voltage at all.

 

[kennethf]

Hi, have an mbp 13" mid 2012 i5 that Iam working on, I have got it to start but there is something strange. It wont boot into os x and it wont start without battery. G3hot is 3.46V and If I remove the battery and measure on pin 1-3 on the board (battery connector) then the voltage goes from 4.5V up to 15V and down again and keeps doing this. Magsafe light is green and sometimes amber, but blinking a litle bit.

 

[greekhero]

Sorry for the delay ..
The measurments are (attachment) . The Megsafe now has a dim light, previously it was solid, looks like i shorted something on the ISL.
Can someone tell what is the component (330) ? I seems burned inside. What does it do ? Where can i found such component ?

Thank you !

Few notes:

1. Your board is 820-2877-B (from the 2nd picture) if I am reading it right. You should find: schematic, which would show you the logical design, and board view (.brd) file that would show how the parts are actually placed on the board. Using the combination, you would be able to furhter investigate.

2. Pin 3 is where the ISL gets notified that an adapter is present. And it outputs on Pin 14 that the adapter is present go ahead. If you have 0v at pin3 this would reflect in 0v on pin 14 as well. Backtrack to R7010, if it has 16.5 v and ISL 3 has 0 it is likely that you have either capacitor c7011 bad or R7011 bad, or ISL6259 itself is bad. If you don't get 16.5V then you would have to back track and find why you are not getting 16.5 on R7010 replacing ISL 6259 is not as bad as it is heard and seen. Follow the youtube videos and you should be able to do it. I would recommend trying first on a dead board before touching a board you hope to revive.

You can see you would need the schematic/boardview; do google searches put board id and words aliases resolved and hopefully you can find it or buy from ebay, check apple schematics.

Good luck!

 

[t0p0ne]

hey, today i replaced the q7035 with one component from another macbook. macbook as before start only with battery and when start make no bong, no display and restart after a bit with fan going to full speed...

g3hot is 3.7v on my multimeter.

with ac i have no voltage at all.

----------

Hi, have an mbp 13" mid 2012 i5 that Iam working on, I have got it to start but there is something strange. It wont boot into os x and it wont start without battery. G3hot is 3.46V and If I remove the battery and measure on pin 1-3 on the board (battery connector) then the voltage goes from 4.5V up to 15V and down again and keeps doing this. Magsafe light is green and sometimes amber, but blinking a litle bit.

I don't have .brd for 820-2567. If you don't get voltage, over voltage ie. 17v?? Or don't have G3hot, you should focus on charger IC U7000 ISL6258A, check surrounding caps & resistors and their paths connect to U7000 see if any short,corrosion or broken traces, i just fixed a MBP 13 2012 (820-3115) with blinking green (sometimes no LED with Magsafe) and result was pin 17 & 18 traces broke off from their capacitor and 2 resistor, so i managed to bridge both of those pins to each side of their connecting cap and voila! green solid LED, fan spins up and displays bright & shine.
Note: you need a scope to help you when checking pins & paths for corrosion, broken pads..

 

[chigwelldave]

on lt3470 i have volt only on pin 8: 17.8volt .should be ok then and that means lt3470 is bad...

Do you have 17v on pin 6? This is the input to the regulator U6990. Also check for shorts on the output as this will shut down the regulator - check across C6999 for a low resistance. The cap itself or something on the G3Hot rail can be shorting. Capacitors are easier to replace than DFN chips!

Regards,

Chigwelldave.

 

[SKRMobiletech]

Macbook Pro 15 Late 2008 #820-2330-A

I have a macbook pro 15" late 2008 that won't start no liquid damage. I probe some area front and back and I have 0Volts reading some of the probes areas. I have a 3.42Volts at the G3HOT. Anybody could give me clue where I start trouble shooting I would really appreciate any input. Thanks

 

[jpdo]

Hi.

Hi have an macbook a1278 with an 820-2879-b logic board, but when i press the power button he has no chime, no fan spinning but the HDD Works because i hear the sound of hdd.

What can be in logic board?

Thanks

 

[t0p0ne]

I have a macbook pro 15" late 2008 that won't start no liquid damage. I probe some area front and back and I have 0Volts reading some of the probes areas. I have a 3.42Volts at the G3HOT. Anybody could give me clue where I start trouble shooting I would really appreciate any input. Thanks

Does your Magsafe light up? Go to page 60 of the schematic and check the G3hot main supply, check voltage on these Q6910, Q6915, U6915, U6990..Also check D6905 see if you get 16V to pin1, if not hook up the working battery and check pin3 if you get 12V there. put your multimeter to continuity and check there ICs to find if anything is shorted to ground, when it beeps on the non-ground pin, then you'll know it's shorted, lookup schematic and check which line the short is at, short can happen on multiple lines depending on how severe it got liquid damaged

----------

Hi.

Hi have an macbook a1278 with an 820-2879-b logic board, but when i press the power button he has no chime, no fan spinning but the HDD Works because i hear the sound of hdd.

What can be in logic board?

Thanks

Fan must pin when logic board receives and powers up unless fan is bad, connector is loose or broken.
Remove HDD, you're not going to need it unless machine boots and POST first, re-connect the fan, check and report back, you should do more detail work before anyone can help you with it

 

[jpdo]

I have tried with other fan but the problem continues.

I have 3.42v on G3HOT. When i put the charger the magsafe put on green light and if i connect the battery he turns the orange light but when i turn the mbp on no fan spining and no chime.

What can i check to give you more details?

The F9800 or R5095 can interfer with this problem?

Thanks

 

[jpdo]

HI. I have tested to reset smc on board and the fan spin for 1 second and then nothing happens.

 

[dellxps15]

Does your Magsafe light up? Go to page 60 of the schematic and check the G3hot main supply, check voltage on these Q6910, Q6915, U6915, U6990..Also check D6905 see if you get 16V to pin1, if not hook up the working battery and check pin3 if you get 12V there. put your multimeter to continuity and check there ICs to find if anything is shorted to ground, when it beeps on the non-ground pin, then you'll know it's shorted, lookup schematic and check which line the short is at, short can happen on multiple lines depending on how severe it got liquid damaged

----------



Fan must pin when logic board receives and powers up unless fan is bad, connector is loose or broken.
Remove HDD, you're not going to need it unless machine boots and POST first, re-connect the fan, check and report back, you should do more detail work before anyone can help you with it

well on the first mac with corrosion on lt3470, i have 0v on pin 6.

on the other mac i have coltge decreasing from pin3 of u7000. it pass from 1-2 volt going to 0.

on this third board, it start, fan spin, all seems ok, but no chime and no post.

i've checked all coils and all have volts except this marked with red lines.