My MacBook Pro doesn't turn on unless it's connected to wall

[imactor]

Hi,

I've got a MacBook Pro 13" mid-2012 standard configuration and a strange thing happen:

- I'm unable to turn on the computer unless the mac is connected to the wall.

- I press the battery indicator button and nothing happens.

- It has a good battery

- The power button is OK

- I connect the computer to the wall and then I'm able to turn it on with the power button and the battery indicator button shows the level of charge.

- When the computer is On, I can disconnect the magsafe and everything it's OK.

- If I turn off the computer being disconnected to the wall and then I try to Turn it on, I unable to do so, forcing me to connect the magsafe and then I can press the power button and everything works.

What could it be?

Thanks.

 

[ISKOTB]

check your battery if it's normal, SMC rest and if not have the laptop checked

 

[Fishrrman]

What's does "Coconut Battery" (free app) tell you about the battery?

 

[imactor]

@itegypt @Fishrrman Everything seems to be OK :-(

 

[DeltaMac]

Design capacity shows that you have less than 80% of original capacity.
Time to think about battery replacement.

But, your symptom of no power until you plug in the magsafe, says failed battery, or the magsafe board is faulty.
As the battery just has a loss of full charge capacity, that shouldn't affect booting, nor need the magsafe for initial power.
I would suspect that the magsafe board is a likely fix. It's probably less than $20 for the part, and not too bad to replace.
If THAT doesn't fix your problem, then it's probably a failure of the logic board.

 

[Dadioh]

Try running Apple Hardware Test (AHT) to check the charging circuit and sensors. Possibly one of the many sensors on the logic board has failed.

https://support.apple.com/en-ca/HT201257

 

[imactor]

Hi, I did the AHT (the extended one) with no issues :-(

 

[Dadioh]

Hi, I did the AHT (the extended one) with no issues :-(

Interesting. The Battery Indicator LEDs (BIL) are a result of communications between the ISL6259 charger, the battery, and the SMC. Having the BIL not light up when on battery power indicates that that communication is not happening and therefore the SMC is deciding to not boot the computer. Once it is booted and you disconnect the charger does the BIL stop working again? Or does the BIL only work while the charger is plugged in?

 

[imactor]

Interesting. The Battery Indicator LEDs (BIL) are a result of communications between the ISL6259 charger, the battery, and the SMC. Having the BIL not light up when on battery power indicates that that communication is not happening and therefore the SMC is deciding to not boot the computer. Once it is booted and you disconnect the charger does the BIL stop working again? Or does the BIL only work while the charger is plugged in?

Thanks for the help!
- When the Macbook is disconnected from the wall, I press the BIL and nothing happens and I can't turn on the Mac.
- I plug the Magsafe and the Magsafe light (Green or Orange) turns on.
- Then I press the BIL and shows the battery charge level.
- Now I'm able to turn on the computer.

:-(

It's very strange.

 

[Dadioh]

Thanks for the help!
- When the Macbook is disconnected from the wall, I press the BIL and nothing happens and I can't turn on the Mac.
- I plug the Magsafe and the Magsafe light (Green or Orange) turns on.
- Then I press the BIL and shows the battery charge level.
- Now I'm able to turn on the computer.

:-(

It's very strange.

Thanks. What I was asking is, once you have booted with the sequence you mentioned above, you can disconnect the charger and it continues to run on battery. But does the BIL still work now with charger disconnected and running off battery?

 

[imactor]

Thanks. What I was asking is, once you have booted with the sequence you mentioned above, you can disconnect the charger and it continues to run on battery. But does the BIL still work now with charger disconnected and running off battery?

Yes.. When the computer is turned on and then I unplug the magsafe, everything works ok (even the BIL).

:-(

 

[DeltaMac]

Replacing the magsafe board is a good next step.

 

[Dadioh]

Yes.. When the computer is turned on and then I unplug the magsafe, everything works ok (even the BIL).

:-(

Ok. It sounds to me what is happening is that the battery is not powering the G3Hot 3.4V supply. Without that 3.4V everything is dead. Once you plug in the charger it powers up the SMC and everything boots. Once running, the 3.4V is maintained by the 12V PBUS power rail.

The G3Hot gets its power through a dual diode and it sounds like one leg of that diode is bad. The one that sends the battery voltage. Next step would be to confirm this with a multimeter. I don’t recall if this is one the top side but I can check.

Are you able to solder? You will also need another diode
[doublepost=1514503372][/doublepost]

Replacing the magsafe board is a good next step.

I don’t believe the DC board is the issue. The Center pin is allowing the signaling for the LED on the MagSafe and it is providing the 16.5V to the logic board so it is doing everything correctly.

 

[imactor]

Ok. It sounds to me what is happening is that the battery is not powering the G3Hot 3.4V supply. Without that 3.4V everything is dead. Once you plug in the charger it powers up the SMC and everything boots. Once running, the 3.4V is maintained by the 12V PBUS power rail.

The G3Hot gets its power through a dual diode and it sounds like one leg of that diode is bad. The one that sends the battery voltage. Next step would be to confirm this with a multimeter. I don’t recall if this is one the top side but I can check.

Are you able to solder? You will also need another diode
[doublepost=1514503372][/doublepost]

I don’t believe the DC board is the issue. The Center pin is allowing the signaling for the LED on the MagSafe and it is providing the 16.5V to the logic board so it is doing everything correctly.

Wow! Thanks for the help!
I have a Multimeter but I'm a Beginner but i'm not able to solder :-(

Where is that diode located? I can take a photo maybe.

Again, thanks for the help.

 

[Fishrrman]

OP:

Sometimes the best solution (or the best one "that works without too much trouble") is a "workaround".

Dadioh seems to have zeroed in on the problem (reply 13 above), but it requires fine soldering skills or perhaps a motherboard replacement.
A high-priced repair may not be worth it on a 5-year-old MacBook.

So... one must find something "that works" and stick with it.
I'd just do this:

- Once you have it powered up, try to keep it on as long as possible without a cold shutdown. Just let it sleep.
- You'll have to be ready to re-charge the battery when needed, of course (or the battery will run down and power off)
- I'm wondering if you can do a "warm restart" without connecting the charger? If so, this is a good practice every few days to "clean out the RAM" and give it a fresh start.

I normally shut my Macs down every night.
But with a peculiar problem such as yours, one must do.... what one must do!