SMC Issue on MBP 13 - Hardware Troubleshooting Guide

[stonewall777]

15" mid 2009 completely dead, no magsafe lights

I was checking the voltage on my DC In board,
and I'm not sure about my results.

Using a right angle 85W magsafe,
voltage is 24.22 vdc across the pins
in the reference photo

Using the straight plug magsafe,
voltage is 6.85 vdc

Is this normal?

I have another logic board that
works normally, and I have used this DC In
board with it, and everything worked fine.
Both logic boards are 820-2533, one -A and
one -B


DC IN Brd 820-2565-02

BTW, the DC IN board was disconnected
when I did the measurements.



I've checked both fuses, the one by the magsafe,
and the one down by the battery connector. And
I get .22 ohms or so, so they seem OK.

But the computer won't boot on the battery or
the magsafe charger. And I did try the SMC bypass
already. And when the magsafe is attached, no
lights come on, neither green or orange.

I want to know if my voltage measurements above
are normal, and then where should I check next?

Thanks.

 

[bex91]

I've had my magsafe replaced twice in a year due to being defective. Sometimes it didn't show any light and didn't charge. I find this a bit odd. Was I unlucky twice, with exactly the same problem in two new magsafe chargers?

I started to wonder... Sometimes when I want to work in a different room I just unplug the magsafe from my mac and leave the charger connected to the power outlet. Could this possibly be the problem? Should I remove my magsafe from the power outlet as well?

Thanks

 

[ZZZAC]

Hi, i have a i5 2011 A1278 Logic board here, and im having G3hot issues.
Naturally G3hot doesnt run through the system on battery (havent tried mains)

and i noticed i wasnt getting any voltage on part of the charging circuit, so i whipped this out and replaced it.
Viola G3hot again, running albeit a little high at 3.5v.
Press the power button. its only reaction was to kill the new charging ic i had installed.
No g3hot anymore...
Anyone come across the charging ic (u700) blowing or could point me in the direction that may cause it? Thanks allot.

I found out the issue was to do with the U6990- I noticed it after pulling the inductor off the logic board, testing the capacitance over the G3hot cap showed it was out of circuit, quickly pulled my u6990 off and replaced it and now its on the fast road to repair.

 

[h4lp m3]

Using a right angle 85W magsafe,
voltage is 24.22 vdc across the pins
in the reference photo

Thanks!
I love threads like this.

 

[ZZZAC]

could do with some help

Right i have another macbook here, it is repetitively blowing the u7000 charging
The g3hot line is playing up and giving me 3,5v of DC, and has around 2-4ohms on g3hot to ground, so iv been pulling components out of the g3hot rail trying to isolate the short.

I have so far
pulled u6900
pulled u6901
pulled u6990
pulled C6990 (way out of tollerence)

But i still have a open to ground on my g3hot.
any of the more experienced guys on here suffer a repetitvely blowing charging ic? or n issue like this?
Anything else you would suggest testing?
Cheers guys- happy repairing

 

[tswartfiguer]

820-2523-B Logic Board

Hello eveyone;

Does anyone on here have, or know where to get the board view file for the 820-2523-B logic board? I have searched for hours on the internet with no luck. I found the Schematic for the board, that doesn't help much when you can't find the components to test. The logic board had water damage when I bought it to repair. The logic board is for a 2009 Macbook Pro A1268 Uni-Body.

I am willing to pay someone for the board view file, whatever it takes to get it, I just don't want to waste the money I spend on the macbook not being able to find what is broken on it.


Thanks in advance for any help and if anyone needs the schematic for the board PM me and I will be happy to share it.

 

[jakeiteasy]

a1278 no power

Hi there, Hope you can help. I have a macbook pro 13 2009 I was changing the display and forgot to disconnect the battery doh ! It now displays the following symptoms:
The magsafe lights as normal .
does nothing when power button is pressed
Does nothing when power pads ( by keyboard ribbon) shorted.
White fuse by battery connector shows 12.61 and hot rail 3.42
the board has not suffered water damage just doesnt seem to power up anymore. Can you give me some idea as to where to go from here. Any help would be really really appreciated cheers jake.

 

[debo160]

Macbook pro 17" 2.5ghz i7 8gb shorted by battery connector cover

Hadn't been to the board in ages. Wow you guys are up to 93 pages. OK I picked up a really nice Macbook Pro 17 Quad Core machines. The computer had been dropped with no water damage at all. The machine would come on but had a dim screen. I took the computer apart checked the backlight fuse and sure enough it was bad. I changed the fuse and the computer lit up like a christmas tree. Everything was in working order. Used it for a few days to make sure always well before putting the item back together. The next day I put everything back together. Everything was done except the cover over the battery. Grabbed the metal cover and went to place it in position and I drop it. The plate hits the board, I see a small spark. I didn't think it was bad until I plugged it in. No green light or orange charge and no boot. I thought the battery was dead but I guess it had enough juice to zap it. I am going to check the fuses but does anyone have a schematic for this board? Im not sure where to start. If anyone has dealt with this any info would be great.
Thanks
Debo160

 

[milkman406]

I have a 2010 Macbook Pro 2.4g

I've read every page of this thread trying to find an answer to the problems my water damaged macbook pro was having, and with a thorough cleaning I managed to get a dim green light on my (brand new) magsafe charger, and I can read a solid 3.36 signal at the G3Hot and everywhere else it's supposed to be that I can find.

I can't get the macbook to even try to start, even when using the various smc bypass methods....

Any help? Tips on what to try next?

 

[chigwelldave]

Hi Milkman406,

Grab the schematic and take a look at the 'Power System Architecture' and 'Power Sequence' pages. Between the two you will see which power rails should be coming on, when and the expected voltages. This will tell you how far you are proceeding into the boot sequence. A boardview in conduction with the schematic will show you where to take your measurements.

Good luck,

Chigwelldave.

 

[ihermoso]

Help me find this smc

I Cant find the Shemathics and don't know the value, i appreciate if you can find for me, or if you have schematics

Macbook Pro 13 Early 2011
Model a1278

 

[tswartfiguer]

Scematic

Image

I Cant find the Shemathics and don't know the value, i appreciate if you can find for me, or if you have schematics

Macbook Pro 13 Early 2011
Model a1278

You are looking for the 820-2936 scematic If I remeber the board number right.

Look back in this thread or search for 820-2936 the scematic is here I downloaded it from here. I think the board view file is attached as well.

 

[milkman406]

Hi Milkman406,

Grab the schematic and take a look at the 'Power System Architecture' and 'Power Sequence' pages. Between the two you will see which power rails should be coming on, when and the expected voltages. This will tell you how far you are proceeding into the boot sequence. A boardview in conduction with the schematic will show you where to take your measurements.

Good luck,

Chigwelldave.

Thanks man, I grabbed the schematics and dove more into this thread - I have a good voltage at the 14 pin on my charger, but my u6901 on the bottom of the board is completely dead. No voltage at all. From what I understand I need to trace the circuit back to the short, but I'm not really sure how to proceed.... any help would be fantastic.

 

[tswartfiguer]

I have a 2010 Macbook Pro 2.4g

I've read every page of this thread trying to find an answer to the problems my water damaged macbook pro was having, and with a thorough cleaning I managed to get a dim green light on my (brand new) magsafe charger, and I can read a solid 3.36 signal at the G3Hot and everywhere else it's supposed to be that I can find.

I can't get the macbook to even try to start, even when using the various smc bypass methods....

Any help? Tips on what to try next?

I know you said you have tried different SMC bypass methods but I thought I would ask if you tried Unplugging power (Both battery and Magsafe) Hold power button for 15 seconds continue to hold power button and plug the magsafe back in continue to hold power button for another 10-15 seconds then release and press power. This has worked for me when nothing else would.

Hope it helps, Do you have all the board view files and schematic for the board? If not let me know I can give them to you. Good Luck.

 

[chigwelldave]

Hi milkman406,

Sounds like you may have deeper troubles than just the Magsafe LED. What happens when you activate the BIL? If you have battery power, the BIL will tell you the SMC, charger circuit and battery are all OK. Also check the voltage on (both sides of) F7040 as this is your main power rail, all others (except G3Hot) are derived from this. You should see 10 volts or more depending on the battery state and over 12v if the charger is working. You can check Q7055, Q7080 and Q7085 to see how far your power is progressing.

Good luck.

 

[tswartfiguer]

Early 2011 MBP 13

Image

I Cant find the Shemathics and don't know the value, i appreciate if you can find for me, or if you have schematics

Macbook Pro 13 Early 2011
Model a1278

Here is some files that might help you

 

[Taz416]

SMC Bypass but no Boot

Hi,

Thanks for all the info from all parties. It is really appreciated.

Round 1 for my MBP 13" Mid-2010 after a spill from a fish bowl was cleaning the board and reassembling.

I have the dim light on the power adapter and bypassed the SMC where I get a chime and a brightly lit screen but no boot, no other beeps and nothing on the screen.

Before I start checking voltages etc is there anything else I should be aware of?

Thanks

 

[tswartfiguer]

Hi,

Thanks for all the info from all parties. It is really appreciated.

Round 1 for my MBP 13" Mid-2010 after a spill from a fish bowl was cleaning the board and reassembling.

I have the dim light on the power adapter and bypassed the SMC where I get a chime and a brightly lit screen but no boot, no other beeps and nothing on the screen.

Before I start checking voltages etc is there anything else I should be aware of?

Thanks

When you cleaned the board, did you do it with 90%+ alcohol and after you did how long did you allow it to dry before plugging it in. I have made the mistake of rushing a bit and it made things much worse for me thats the only reason I ask.

 

[markobb]

Hello,

i got MBP 13 2009 mid, i a accidently drag screwdriver on the area wichyelow circle marks, i think only 2 pins was in short-circuit and i saw spark, thats it and mbp wont startup anymore. Is there posible to be damaged on a fuse or something similar?

On 3hot pads and 4pin is 3.4V, on right side 3 element has 0V on them.
Magsafe light green and wont switch to orange for charging battery.
Chargin IC has 2.3v on pin 14.

 

[chigwelldave]

Taz416,

You sound like you're at the 'boot from disk' stage so I'd try it again with an external monitor plugged in via the MDP to see if you get the Apple logo. If so, you could have a problem with the LVDS connector.

Markobb,

The chip in the south-west corner of your circle is for the 3v3 and 5v main power supplies, I'd check these are running.

Regards,
Chigwelldave.

 

[markobb]

Taz416,

Markobb,

The chip in the south-west corner of your circle is for the 3v3 and 5v main power supplies, I'd check these are running.

Regards,
Chigwelldave.

Tnx, do you know what data should i read from pins, maybee have schematic of it?

 

[chigwelldave]

Hi Markobb,

You need the K6 schematic (820-2879) which should be back in the thread somewhere. U7200 pin 16 should be around 12v (or a little less depending on your battery), the feedback pins (2 and 5) should be at around 2v. Pin 2 is feedback for the 5v supply, pin 5 for the 3v3 rail. There is also a power good signal on pin 23 which should be high.

Regards,
Chigwelldave.

 

[markobb]

Hi Markobb,

You need the K6 schematic (820-2879) which should be back in the thread somewhere. U7200 pin 16 should be around 12v (or a little less depending on your battery), the feedback pins (2 and 5) should be at around 2v. Pin 2 is feedback for the 5v supply, pin 5 for the 3v3 rail. There is also a power good signal on pin 23 which should be high.

Regards,
Chigwelldave.

If the white dot on the u7200 is pin 1 and others goes counterclockwise than i get only on pin 16 (12V) on other pins is 0V. The shortcircuit was probably around pins 12-16 if i recal right

 

[chigwelldave]

Hi Markobb,

You may have killed your U7200 or any of the switching transistors Q7260, Q7261 and Q7220. Please see the attached page from the schematic and, just after pushing the power button (or pads) check P5V3V3_REG_EN (should be high), P5VS3_EN_L (should be low) and P3V3S5_EN_L (should be low). ENTRIP1 and ENTRIP2 should both be above 0v.

Regards,
Chigwelldave.

 

[markobb]

Hi Markobb,

You may have killed your U7200 or any of the switching transistors Q7260, Q7261 and Q7220. Please see the attached page from the schematic and, just after pushing the power button (or pads) check P5V3V3_REG_EN (should be high), P5VS3_EN_L (should be low) and P3V3S5_EN_L (should be low). ENTRIP1 and ENTRIP2 should both be above 0v.

Regards,
Chigwelldave.

Today i got same mbp13 laptop but less powered procesor(few diferent elements but u7200 is the same) wich startup with dongle sound but no picture and i mesure pins of u7200 on it and if its

if powered off i get:

pin 16 (12V)
pin 2 (0V)
pin 5 (0.02V)
pin 23 (0V)

if powered on:

pin 16 (12V)
pin 2 (2V)
pin 5 (2V)
pin 23 (3.2V)

So it seem that what are you said about values that this is for powered on computer couse in that case data mach. Or i can assume that u7200 is in this case ok?

About switching transistors Q7260, Q7261 and Q7220 can you show me on pcb where they are. It looks like they are on other side? OK i found them on other side.

For P5V3V3_REG_EN (should be high) on pin 13, nothing hapened when i push ON button,
P5VS3_EN_L (should be low) and P3V3S5_EN_L (should be low) i cannot mesure and press on button, maybe if the pins were on the same side as u7200.
ENITRIP1 0V ENTRIP2 always 0.1V