SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[bladerex]

I am working also on a 1278 MBP board ... and this one have problem
to charge the battery and working with both magsafe and battery together.
It works on battery, it works on magsafe but it freezes if I attach both.

But very strage thing is that if I put a bit of Isopropilic alcohol on
u7000 (alias isl6259) it works for a couple of minutes and charges
the battery. When the alcohol dries it fall back to the previous status.

Can someone explain me why?

I know, the measuring is a most annoying part of our job, but we can not skip it ...... measure around isl6259 all resistors and capacitors and also to ground (with your multimeter set to diode mode and red probe to ground). Compare the measurements with a known good board if ti is possible and you will find the problem.
See also what you get on CHGR_BGATE pin on isl.... from what you say seems that charger can't open Q7055. May also be a dead Q7055 dead (shorten) C7026.
How many % CPU usage do you have when it runs try to check with XRG.

 

[saronno]

I know, the measuring is a most annoying part of our job, but we can not skip it ...... measure around isl6259 all resistors and capacitors and also to ground (with your multimeter set to diode mode and red probe to ground). Compare the measurements with a known good board if ti is possible and you will find the problem.

Yes, thanks ... in the end is the only way.
Anyway, I wonder why the alcohol make it happy ....
it doesn't conduct current so I don't think it changes impedances
around the chip.

 

[bladerex]

Yes, thanks ... in the end is the only way.
Anyway, I wonder why the alcohol make it happy ....
it doesn't conduct current so I don't think it changes impedances
around the chip.

No it does not but helps cooling elements and you know what happens with a resistance with temperature change.....

 

[saronno]

No it does not but helps cooling elements and you know what happens with a resistance with temperature change.....

Maybe you are right ... I will try to do the same thing with a can
of air .... I am curious

 

[bladerex]

Maybe you are right ... I will try to do the same thing with a can
of air .... I am curious

Couple minutes after this conversation I receive one board with the exakt same issue ...... it was no connection between r7051(pin2) and r7050 (pin1,3) and also connection between r7052(pin2) and r7050 (pin2,4) was gone. After two bridges everything works fine.

 

[raginspo]

I've got a late 2008 unibody MBP and had the same symptoms as noted early on in this thread - no temp readings, fans at max, and battery not showing up or indicating any power level on the side of my computer. This all started after my computer died randomly twice in a day. I removed the battery and have been using it without since. Oddly enough, today my computer came back around and everything started working normally, though the sudden shutoffs started occurring again. I used the "smc work around" and I'm back to full speed fans but no crashes.

It seems the problem is likely a corroded SMC and the fix is 99% alcohol and a toothbrush?

 

[eki84]

Hi everybody,

i have a big problem with the macbook from my sister. It has a liquid damage. First, does not turn on and no battery charging. Now ive replaced the ISL6259 and at least the battery is charging. But still does not turn on. Ive replaced the TPS 51125 with a new one but still no boot. When it is quiet, you can hear a "click" comes from the fan and a minimal movement of it. But no other reaction. I hope you guys have an idea... Thanks and regards from germany.

no ideas???

 

[bladerex]

no ideas???

Hi from Germany,
Have you searched for a shorts between all inductors and ground in diode mode?
It seems to me that some of voltages have dead schort to ground and system shuts down to prevent something wronger to happen.
Also it is good to check wich voltages are present and wich not, do you have all the voltages for S5 stage?

 

[alz0rz]

Hello all, what a great thread this is, I've been scavenging from it trying to figure out my problem with no luck. Here is my situation.

Early 2011 MBP. Logic Board: 820-2915-B

The Magsafe light is very very dim green and that is all, no power, nothing.

I am getting good voltages from DC-in board. So after some reading I jumped to checking U7000.

U7000 Pin 3 reads 0V which is the reading I'm getting from R7011.
R7010 I am getting 16.5V on one side and 0V on the other. I read I'm supposed to be getting about 4V out of here?

Does anyone have any suggestions? Thanks!!

Does anyone have any ideas about this situation?

 

[Nicohend]

Does anyone have any ideas about this situation?

So apparently either R7010 or R7011 is toasted. Grab your multimeter and measure (with MagSafe and battery disconnected!) the resistance of R7010 and R7011. I guess that either R7010 is infinite or R7011 is shorted.

 

[alz0rz]

So apparently either R7010 or R7011 is toasted. Grab your multimeter and measure (with MagSafe and battery disconnected!) the resistance of R7010 and R7011. I guess that either R7010 is infinite or R7011 is shorted.

With power disconnected,

R7010 reads 30 kilo-ohms, R7011 reads only 1.6 Ohms.

 

[bladerex]

With power disconnected,

R7010 reads 30 kilo-ohms, R7011 reads only 1.6 Ohms.

R7010 30.1K 1%
1/16W MF-LF 402

R7011 9.31K 1%
1/16W MF-LF 402

Either R7011 is blown or C7011 shorting. Remove R7011 and measure again, if short is still there than it is C7011.
From schematics "ACIN pin threshold is 3.2V, +/- 50mV
Divider sets ACIN threshold at 13.55V"

 

[bladerex]

Hi!

I have a 15" MBP A1286 mid 2010 i5 2.4GHz that died suddenly while on battery. After that the laptop doesn't boot or charge battery. Magsafe has only green led on. SMC reset does nothing and LB part number is 820-8250-A.

I think you have 820-2850-A.
Try also measuring R7080, R7081, R7085, R7086 and Q7080, Q7085. I recently had a board with bad Inrush limiter and bad reverce current protection with same symptoms.

 

[saronno]

Couple minutes after this conversation I receive one board with the exakt same issue ...... it was no connection between r7051(pin2) and r7050 (pin1,3) and also connection between r7052(pin2) and r7050 (pin2,4) was gone. After two bridges everything works fine.

I made a disaster: since r7051 was 90 ohm I thought
the problem was there. Unfortunatly I had not a 2.2 ohm resistor
to replace it .... and since the other one was almost zero (r7052)
I had a great idea: come on ... short the damn bastard (r7051).

I insert the battery and ...... an evil burning smell rise from the
poor board.

The thing is ... why? I can't burn the board with a similar short.

I think that there was also a short under the chip and the 2.2 ohm resistor
(90 ohm actually) made some sort of protection for the shorted chip.

 

[bladerex]

I made a disaster: since r7051 was 90 ohm I thought
the problem was there. Unfortunatly I had not a 2.2 ohm resistor
to replace it .... and since the other one was almost zero (r7052)
I had a great idea: come on ... short the damn bastard (r7051).

I insert the battery and ...... an evil burning smell rise from the
poor board.

The thing is ... why? I can't burn the board with a similar short.

I think that there was also a short under the chip and the 2.2 ohm resistor
(90 ohm actually) made some sort of protection for the shorted chip.

Or you have shorted something else too....

 

[mihkels]

I have an Early 2011 13" MBP that had a small amount of liquid spilled on it. I cleaned the logic board even though there was no visual damage do it.
Everything works perfectly - the computer turns on, the battery is discovered etc. but the charging works erratically.
Most of the time the Magsafe shows a very dim green light and doesn't charge the battery. But sometimes, it randomly starts charging and everything seems fine until I unplug the charger. Already tried SMC and PRAM reset but that didn't help.
I tested with another battery and Magsafe charger but the problem still persists.

Can anyone tell me what could cause such a weird problem or where to look on the motherboard?

 

[bladerex]

I have an Early 2011 13" MBP that had a small amount of liquid spilled on it. I cleaned the logic board even though there was no visual damage do it.
Everything works perfectly - the computer turns on, the battery is discovered etc. but the charging works erratically.
Most of the time the Magsafe shows a very dim green light and doesn't charge the battery. But sometimes, it randomly starts charging and everything seems fine until I unplug the charger. Already tried SMC and PRAM reset but that didn't help.
I tested with another battery and Magsafe charger but the problem still persists.

Can anyone tell me what could cause such a weird problem or where to look on the motherboard?

Post some pictures of the charging chip, also on R7050 and around it....

 

[mihkels]

Post some pictures of the charging chip, also on R7050 and around it....

Could you help me with locating the charging chip?

And the same thing happened again - I went to sleep and left the Magsafe connected to the computer with a dim green light. Woke up to the charger glowing orange and the battery fully charged. It seems that the charger has to be connected for more that 5 hours before it starts charging.

 

[saronno]

Or you have shorted something else too....

Mmmmm ... I don't think so ... I check the bridge with microscope
and with the multimeter before plug in the battery.
The resistor was 90 ohm ... It should have been 2.2 ohm
that protected the chip that was probably shorted
internally or under the chip (this board has a liquid damage).

I don't see any other reasonable explanation ... somehow the
input impedance was very very low ....

however ... talking about the other one .... do you have any experience
with board having cpu with 1,05V but lacking 1,25V?
I am talking about tipical core 2 duo cpu ... there are the line powering the
cpu .... one is 1,05V (PP1V05_S0_CPU) and the other one is 1,25V
(PPVCORE_S0_CPU).I remeber that this one is not a MBP board but
a unibody white board (a1342).

Checking ALL_SYS_PWRGD ... is 0v ... so I checked the output of
the various chip connected to ALL_SYS_PWRGD .... they are all good
but ISL88042. This chip monitors three tensionsP3v3_s0,PP1v05_s0 and
PP1v5_s0.

The last one is just 0.28V the other ones are good.

The chip responsible for that tension is u7300 (tps51116) ... I checked
the output on the smoothing inductor (l7329) .... and is not good (0,28 V)
I made also a rapid check of q7320 and q7321 .... the mos used to generate
that voltage and they seems good (not shorted al least).

The problem is u7300 is not powered up ! It's powered by PP5V_S3_1V5S30V75S0 .... a derivation of PP5V_S3_REG.
But PP5V_S3_REG is present and PP5V_S3_1V5S30V75S0 is not !

I tested another board ... and there is solid connection between
c7302 pin1 and L7260 pin1 (two good test point for the two tensions). On this one there is no connection at all !

So my guess is the board took a hit and there is a broken trace ...
where is very difficult to say if not impossible since the board is multilayer.

 

[mihkels]

Post some pictures of the charging chip, also on R7050 and around it....

Here's two pictures of the R7050 and Q7055.

I see that I'm missing R7002 and R7010.

 

[saronno]

...

I tested another board ... and there is solid connection between
c7302 pin1 and L7260 pin1 (two good test point for the two tensions). On this one there is no connection at all !

So my guess is the board took a hit and there is a broken trace ...
where is very difficult to say if not impossible since the board is multilayer.

Anyway ... before trying a bypass, I'd like to hear other opinions.

Bypass done

Everything fine !

 

[Monkeywrap]

I think you have 820-2850-A.
Try also measuring R7080, R7081, R7085, R7086 and Q7080, Q7085. I recently had a board with bad Inrush limiter and bad reverce current protection with same symptoms.

You're right it's a 820-2850-A. I measured all those resistors and both Q7080 and Q7085. All resistors and Q7080 seem to be ok and Q7085 has steady voltage on pins 1-3 but fluctuating voltage between 4V-16V on pins 4-8. Looked the part everywhere but no luck... any chance someone here has one available?

Part is Renesas HAT1128R01-EL-E

 

[darkdead]

Hello i just got a 1278 evrything is ok less the fan at 6400rpm rest is ok.

whit old and new battery pluged the fan go to 6400 rpm (smc fan lno works) and whit mag safe only it work fine smc and fan control works.
¿any idea what is worng?
All comps temps are ok no water damage.

 

[bladerex]

Mmmmm ... I don't think so ... I check the bridge with microscope
and with the multimeter before plug in the battery.
The resistor was 90 ohm ... It should have been 2.2 ohm
that protected the chip that was probably shorted
internally or under the chip (this board has a liquid damage).

I don't see any other reasonable explanation ... somehow the
input impedance was very very low ....

however ... talking about the other one .... do you have any experience
with board having cpu with 1,05V but lacking 1,25V?
I am talking about tipical core 2 duo cpu ... there are the line powering the
cpu .... one is 1,05V (PP1V05_S0_CPU) and the other one is 1,25V
(PPVCORE_S0_CPU).I remeber that this one is not a MBP board but
a unibody white board (a1342).

Checking ALL_SYS_PWRGD ... is 0v ... so I checked the output of
the various chip connected to ALL_SYS_PWRGD .... they are all good
but ISL88042. This chip monitors three tensionsP3v3_s0,PP1v05_s0 and
PP1v5_s0.

The last one is just 0.28V the other ones are good.

The chip responsible for that tension is u7300 (tps51116) ... I checked
the output on the smoothing inductor (l7329) .... and is not good (0,28 V)
I made also a rapid check of q7320 and q7321 .... the mos used to generate
that voltage and they seems good (not shorted al least).

The problem is u7300 is not powered up ! It's powered by PP5V_S3_1V5S30V75S0 .... a derivation of PP5V_S3_REG.
But PP5V_S3_REG is present and PP5V_S3_1V5S30V75S0 is not !

I tested another board ... and there is solid connection between
c7302 pin1 and L7260 pin1 (two good test point for the two tensions). On this one there is no connection at all !

So my guess is the board took a hit and there is a broken trace ...
where is very difficult to say if not impossible since the board is multilayer.

Since you don't have short to ground, I think it's safe to bridge them. But first check for short to ground, and make sure that they must be connected!!!

----------

Bypass done

Everything fine !

Congratulations

----------

You're right it's a 820-2850-A. I measured all those resistors and both Q7080 and Q7085. All resistors and Q7080 seem to be ok and Q7085 has steady voltage on pins 1-3 but fluctuating voltage between 4V-16V on pins 4-8. Looked the part everywhere but no luck... any chance someone here has one available?

Part is Renesas HAT1128R01-EL-E

I am from Germany and I think it isn't a good idea to send you one , maybe you can try salvaging from a old board? It's not need to be the same model board. But those transistors go bad veeeeeery rear.

 

[Monkeywrap]

I am from Germany and I think it isn't a good idea to send you one , maybe you can try salvaging from a old board? It's not need to be the same model board. But those transistors go bad veeeeeery rear.

I don't have spare board but I'm in no hurry so why not start looking for defective board that has the part. But if you have that part I can pay for postage to Finland.