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mxtr185

macrumors newbie
Aug 6, 2014
2
0
A1278 Early 2011 bad 625AHRTZ

Hello,

I am new to this forum and I am working on trying to resurrect my first MBP

I recently purchased an early 2011 A1278.
Laptop is not responsive to anything and it is showing a dim green light that is not blinking.
There was some corrosion on the board primarily around the 625AHRTZ.
Prior to cleaning, this chip would get extremely hot when the magsafe was plugged in.
I was able to clean up the corrosion and now the magsafe indicator is showing bright green but still there is no response. I do not have a way to charge the battery to be able to tell if it will respond to a charged battery. If there is a bad 625AHRTZ would it prevent the laptop from booting off of the magsafe or does this just prevent it from charging? Any information would help, I have a scrap board that I can use to get a replacement chip if needed. Any advice would be helpful.

Thank you
 

Sheridansystems

macrumors member
Aug 27, 2013
36
0
SoCal
finding schematic documented voltage?

Hello,
Hi,
On the A1278 K24.pdf Page 58, the "Battery Connector" has no voltages listed on the circuit paths? I do know the needed voltage for that connector but How do I find voltage level readings seemingly not listed on the schematic?
Thanks in advance
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
Hello,

I am new to this forum and I am working on trying to resurrect my first MBP

I recently purchased an early 2011 A1278.
Laptop is not responsive to anything and it is showing a dim green light that is not blinking.
There was some corrosion on the board primarily around the 625AHRTZ.
Prior to cleaning, this chip would get extremely hot when the magsafe was plugged in.
I was able to clean up the corrosion and now the magsafe indicator is showing bright green but still there is no response. I do not have a way to charge the battery to be able to tell if it will respond to a charged battery. If there is a bad 625AHRTZ would it prevent the laptop from booting off of the magsafe or does this just prevent it from charging? Any information would help, I have a scrap board that I can use to get a replacement chip if needed. Any advice would be helpful.

Thank you

If you have bad charger circuit, never power on.
You need to replace this ISL.
 

TheTuesdaydude

macrumors newbie
Jun 11, 2013
20
8
MBP 13" mid 2012

hi, i just got some water on my MBP 13" mid 2012. and now it will not power up at all, i can´t reset the SMC because i´m afraid the keyboard is done.
I was looking for a way to jumpstart the macbook, but even after spending hours in forums nobody seems to know where the "power-on pads" on this models logic board are located.

would be awesome if somebody could help.
thx

sorry for my english i am not a native speaker :)
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
hi, i just got some water on my mbp 13" mid 2012. And now it will not power up at all, i can´t reset the smc because i´m afraid the keyboard is done.
I was looking for a way to jumpstart the macbook, but even after spending hours in forums nobody seems to know where the "power-on pads" on this models logic board are located.

Would be awesome if somebody could help.
Thx

sorry for my english i am not a native speaker :)

here
 

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nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
LVDS Interference A1278 2011

Hi, liquid damage board fixed.
Now there is interference on LCD image.

i replaced lvds connector but has the same issue.
As show in the imege some horizontal lines.

If you have experienced this issue, let me know:)
 

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ZZZAC

macrumors regular
Dec 29, 2013
101
2
ALB repairs uk
hi, i just got some water on my MBP 13" mid 2012. and now it will not power up at all, i can´t reset the SMC because i´m afraid the keyboard is done.
I was looking for a way to jumpstart the macbook, but even after spending hours in forums nobody seems to know where the "power-on pads" on this models logic board are located.

would be awesome if somebody could help.
thx

sorry for my english i am not a native speaker :)

2012 and 2011 boards power on by themselfs when the battery is unplugged.
 

Yako76

macrumors member
Jul 2, 2011
44
0
Service Manual

Hi Friends,

I'm looking for this two MBA 13

Mid 2011, Mid 2012

Anybody has it?

Thanks a lot!!!
 

ZZZAC

macrumors regular
Dec 29, 2013
101
2
ALB repairs uk
yeah. no it´s not powering on. :(
check the 3.3v and 5v coils
L7220 and L7260 on the schematic.
If you have 3.3v but no 5v check to see if you get Pgood from the 5v 3.3v regulator

----------

I should probably know this one
i have an a1342 board here that seems to function perfectly apart from it wont power on from the battery, it will however run of it and charge it
i think its the SCL line that is not 3.4v and i cant figure out whats causing it to be low considering the SDA line is fine and it charges.

anyone seen the problem of not powering via the battery like this? but strange
already ruled out the charging chip, that was the initial fault the baord had (and ive replaced it a second time to ensure i didnt mess up the soldering job.
will do my own checks later but ive got more logic boards than i have time for.... :)
 

triplelucky

macrumors regular
Sep 30, 2012
153
0
Tucson, Arizona, USA
The 2011’s power on when power is first applied after being removed.

The “power on pads” would be SMC_ONOFF_L located at R015 on the 2914 boards, for instance.

Also SMC_MANUAL_RST_L at R5001 can be useful in troubleshooting.
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
check the 3.3v and 5v coils
L7220 and L7260 on the schematic.
If you have 3.3v but no 5v check to see if you get Pgood from the 5v 3.3v regulator

----------

I should probably know this one
i have an a1342 board here that seems to function perfectly apart from it wont power on from the battery, it will however run of it and charge it
i think its the SCL line that is not 3.4v and i cant figure out whats causing it to be low considering the SDA line is fine and it charges.

anyone seen the problem of not powering via the battery like this? but strange
already ruled out the charging chip, that was the initial fault the baord had (and ive replaced it a second time to ensure i didnt mess up the soldering job.
will do my own checks later but ive got more logic boards than i have time for.... :)

SDA / SCL -> SMC -> Battery charger. i fix some mbpro with low voltages in this lines. Replacing SMC fix this problem.
 

ZZZAC

macrumors regular
Dec 29, 2013
101
2
ALB repairs uk
hi, i just got some water on my MBP 13" mid 2012. and now it will not power up at all, i can´t reset the SMC because i´m afraid the keyboard is done.
I was looking for a way to jumpstart the macbook, but even after spending hours in forums nobody seems to know where the "power-on pads" on this models logic board are located.

would be awesome if somebody could help.
thx

sorry for my english i am not a native speaker :)

SDA / SCL -> SMC -> Battery charger. i fix some mbpro with low voltages in this lines. Replacing SMC fix this problem.


ill reflow it first and see what happens
Ive had a SCL issue before even after replacing the frickin smc though so i dont want to jump to conclusion.

i think i have some SMC's on the way from china, there's no harm replacing it and hoping it fixes it :)
 

tiagobaracho

macrumors regular
Jun 27, 2014
105
0
schematics

hi guys... do you have schematics and board view for this two boards
820-2915-B
820-2850-A
Thanks a lot !
 

ZZZAC

macrumors regular
Dec 29, 2013
101
2
ALB repairs uk
Still no power from magsafe, only from battery.
I will check SMC resistors.

Hi bud
i have two 820-3115 boards with the same problem as you where stating
all works but no signal from ISL
measured the pullup for the signal and there's definatley a short on the line (measures 13k rather than 470k)

ill see if the short is still there with the powerguard But my honest fealing is the newer model SMC is more prone to failure than the pre 2012 boards.

I already have 10 or so on there way from china but please get back to me if you have had any success.
Thanks
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
Hi bud
i have two 820-3115 boards with the same problem as you where stating
all works but no signal from ISL
measured the pullup for the signal and there's definatley a short on the line (measures 13k rather than 470k)

ill see if the short is still there with the powerguard But my honest fealing is the newer model SMC is more prone to failure than the pre 2012 boards.

I already have 10 or so on there way from china but please get back to me if you have had any success.
Thanks

Im working on this board today and take some measurements

U700:

Pin 1 : 12 v instead 0v
Pin 14: 1.2 v

I check divider resistors from FET and are working well.
Im confused, i think maybe is a Q7030-Q7035 defective.

im agree... SMC in 2011 and 2012 are in the wrong side of the board
 
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smithtony22

macrumors newbie
Nov 4, 2012
7
0
820-3115 mid 2012 13 MBP

Im working on this board today and take some measurements

U700:

Pin 1 : 12 v instead 0v
Pin 14: 1.2 v

I check divider resistors from FET and are working well.
Im confused, i think maybe is a Q7030-Q7035 defective.

im agree... SMC in 2011 and 2012 are in the wrong side of the board

Hi there, would it be possible that you can send me or upload the schematic and board view file, for this model [820-3115 mid 2012 13 MBP]? I would so much appreciate if you can. Many thanks
 

ZZZAC

macrumors regular
Dec 29, 2013
101
2
ALB repairs uk
Hi there, would it be possible that you can send me or upload the schematic and board view file, for this model [820-3115 mid 2012 13 MBP]? I would so much appreciate if you can. Many thanks

search the thread ive already posted it.... :rolleyes:


Im working on this board today and take some measurements

U700:

Pin 1 : 12 v instead 0v
Pin 14: 1.2 v

I check divider resistors from FET and are working well.
Im confused, i think maybe is a Q7030-Q7035 defective.

im agree... SMC in 2011 and 2012 are in the wrong side of the board

Ahh
on check for the stability of Q7080 and Q7085. ive had issues with these fets before, not short but instable voltage causing problem.

See both my boards have 12v output.
Both also have no green light, one of them has 3.1v on pin 14, the other has 0v

messed about with all possibilities. think its the smc on both of these, The model between 2011 and 2012 changed from a Hitachi chip to some other one and i believe these other SMC chips can fail more than the Hitachi chip but ill find out when i do more 2012 board repairs.

----------

So i pulled the smc (all be it far to quickly pulling a unconnected pad)
i can confirm the short on smc bc ac ok has also lifted with the smc so its clear now that is the problem
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
search the thread ive already posted it.... :rolleyes:




Ahh
on check for the stability of Q7080 and Q7085. ive had issues with these fets before, not short but instable voltage causing problem.

See both my boards have 12v output.
Both also have no green light, one of them has 3.1v on pin 14, the other has 0v

messed about with all possibilities. think its the smc on both of these, The model between 2011 and 2012 changed from a Hitachi chip to some other one and i believe these other SMC chips can fail more than the Hitachi chip but ill find out when i do more 2012 board repairs.

----------

So i pulled the smc (all be it far to quickly pulling a unconnected pad)
i can confirm the short on smc bc ac ok has also lifted with the smc so its clear now that is the problem

Are you using 0.45 balls for SMC?
If you have trusted retailer for this component please let me know in private message.

Regards

I will work in other 2010 13" boards today, some with all functional signs but no power on.
 

Yako76

macrumors member
Jul 2, 2011
44
0
Macbook A1342 no power on

Hi Guys,

my MB A1342 won't power on. LED of Magsafe light norman, charge Battery is also ok.
Can anybody explain how I have to procede? I have Schematics and BV of this board, also Microskop and multimeter.

I appreciate any suggestion.

Thanks a lot my friends!!!
 

nicoar10

macrumors member
Oct 15, 2013
53
1
Spain
Hi Guys,

my MB A1342 won't power on. LED of Magsafe light norman, charge Battery is also ok.
Can anybody explain how I have to procede? I have Schematics and BV of this board, also Microskop and multimeter.

I appreciate any suggestion.

Thanks a lot my friends!!!

i fixed some A1342 with no power issue.
If you have g3hot and battery driver working, you have green light.

Check battery fuse, you will see 12V. Next check TPS51125 5v3v regulator.
 

Yako76

macrumors member
Jul 2, 2011
44
0
i fixed some A1342 with no power issue.
If you have g3hot and battery driver working, you have green light.

Check battery fuse, you will see 12V. Next check TPS51125 5v3v regulator.

Hello Nicoar,

many thanks for your help.
The Battery fuse is ok.
I will chek the TPS51125 and tell you the voltages.
 

dellxps15

macrumors member
Oct 22, 2013
86
0
check the 3.3v and 5v coils
L7220 and L7260 on the schematic.
If you have 3.3v but no 5v check to see if you get Pgood from the 5v 3.3v regulator

----------

I should probably know this one
i have an a1342 board here that seems to function perfectly apart from it wont power on from the battery, it will however run of it and charge it
i think its the SCL line that is not 3.4v and i cant figure out whats causing it to be low considering the SDA line is fine and it charges.

anyone seen the problem of not powering via the battery like this? but strange
already ruled out the charging chip, that was the initial fault the baord had (and ive replaced it a second time to ensure i didnt mess up the soldering job.
will do my own checks later but ive got more logic boards than i have time for.... :)

i have the exact same problem: no 5v but 3.3volt available. changed u7200 and still the same. pin 23 pgood is 0volt...

q7221 pin 2 is 3.3volt, pin 6 is 0volt

on u7000 i have:
pin1 0v
pin2 16v
pin3 4v
pin4 3.3volt
pin 16 oscillate from 16 to 9v

pin 19 and 20 5volt
pin 23, 26 and 27 16volt

compared to another macbook board, i have 4volt more;
where i should have 12,5volt i have 16,5

when volt on pin 16 go from 9 to 16 , 16 to 9 and so on, on the other board i have 5-12 volt oscillation
 
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