How Get Macbook Battery to Charge Again

1. What is MacBook battery not charging issue?

A MacBook battery non charging problem ways that yous can turn on your MacBook, but the charger will not accuse the battery. In other words, your MacBook is mostly working well except for the bombardment charging function. The following symptoms indicate that yous have a MacBook Air or MacBook Pro not charging problem:

1. You go the message "Battery is not charging" in the status menu.
2. You accept the bulletin "No battery available" in the condition menu.
3. You don't have a green calorie-free or orange light on the MagSafe connector.
4.  The condition carte shows your battery is normal and fully charged. But if you lot remove the charger, the MacBook will plow off instantly.

Many people go confused betwixt "MacBook battery not charging" and "MacBook not turning on". A MacBook with battery charging problem tin be turned on if you connect a working charger to it.  On the other hand, a "MacBook not turning on" problem means that when you lot press the power button on the MacBook keyboard, no matter yous connect a working charger to it or not, you can't see anything on the Mac screen, no chime, no low-cal on the keyboard and no fan-spinning noise. In other words, the MacBook has no sign of life at all. If your MacBook can not turn on, run into our article MacBook Won't Turn On? 10 Ways To Fix Information technology.

2. Why is my MacBook battery non charging?

MacBook battery charging system consists of four components: a charger, a battery, a charging circuit and an SMC chip. Any of these components gone wrong would cause the MacBook Air or MacBook Pro not charging.

1. MagSafe charger or USB-C charger. It delivers power to your MacBook and its battery.
2. Battery. Information technology stores power (charging) and provides power (discharging).
3. Charging circuit. It converts the charger voltage to run your Mac and charges the battery.
4. System Management Controller (SMC).  Information technology controls the behaviour of the charging excursion including start or terminate charging the battery.

Faulty chargers, faulty batteries and wrong SMC data account for the majority of MacBook not charging issues. Fortunately, these faults are easy to set up. Faults in the charging circuit are hard to set and we discuss information technology in the final department.

If you detect the Bombardment Condition card says Not Charging, and the bulletin disappears later, your MacBook should exist fine. Y'all could see the temporarily Not Charging bulletin for several reasons:

1. You apply a low-power adopter. The power adapter barely provides enough power to run your MacBook, but not enough power to charge the battery. For instance, if y'all connect a Macbook Air charger (45W) to a 15" MacBook Pro (85W charger required), you could get the battery not charging notification. If you plough off the Mac or put it to slumber, the power adapter volition start charging the Mac.
2. Safety business organization. If you connect your Mac to an airline power adapter, your Mac might non charge the bombardment, even if you turn off your Mac or put it to slumber. Yous can even so use your Mac without draining its battery. For safety reason, charging a battery in an aeroplane is considered a risk chore.
3. Running high-operation apps. If your Mac is running high-performance applications such as video editing software and video games, the Mac battery may non be charged. If the apps demand more power than the adopter tin provide, your Mac will combine the adopter ability and bombardment ability to run the MacBook in lodge to meet the high ability need. This is an Apple pattern feature to boost performance on demand. If the apps drain the bombardment too chop-chop, you lot may need to pause the apps and let your Mac start charging the battery. If you switch off the Mac, the adapter will accuse the Mac much quicker.
4. Extending battery life. Your bombardment may drain to 90% or lower before it begins charging again. This is a blueprint feature to extend the life of your MacBook lithium-ion battery. You tin can plow off battery health management in Energy Saver preferences. Nosotros don't suggest you lot change the setting unless you take a special need.

3. How does a MacBook accuse its battery?

In society to quickly diagnose and fix the Mac battery not charging issue, you need to know how a MacBook charges its battery. There are two types of MacBook chargers: MagSafe charger and USB-C charger. Apple discontinued the MagSafe chargers in 2015-16.

Magsafe Charger

The output voltage of a Magsafe charger is stock-still . A MacBook Air charger outputs14.5V. A MacBook Pro charger outputs16.5V, xviii.5V or 20V depending on the model.

When you connect a MagSafe charger to the MacBook, the SMC will "handshake" with the info-chip inside the Magsafe connector to identify the charger type including voltage output, current output, manufacturer code and so on. If the charger meets the criteria, the SMC turns on the green light on the connector. This dark-green lite tells you that the SMC has successfully identified a suitable charger for your MacBook.

The SMC volition also "handshake" with the info-chip inside the battery to identify the bombardment type including the working voltage, manufacturer code, electric current temperature so on. Based on the data received from the charger and the battery, SMC determines whether or non to charge the battery and how much corporeality of current will apply to the battery cells.

SMC will tell the charging circuit to start charging the bombardment if ALL the following weather are met:

1. The MagSafe charger has plenty power to power-on the MacBook and charge the battery at the aforementioned time.
2.  The temperature of the bombardment is normal and the bombardment is not fully charged.
3.  The charging circuit detects NO over-current or over-temperature.

While the SMC controls the charging circuit to accuse the battery, it turns on the orange light on the connector. The orange lite tells you that the charger is currently charging the battery.

When the battery is fully charged, SMC will cut off the current flowing into the battery to prevent overcharging the battery. The SMC then changes the lite colour to green. This time the greenish lite tells y'all that the charger has completed the charging task. The charger at the moment only provides plenty power to ability on your MacBook if the MacBook is on.

USB-C Charger

The output voltage of a USB-C type charger is not fixed . The USB-C charger volition negotiate with the MacBook to work out an optimal output voltage dynamically. A USB-C charger could output 5V, 14.5V and 20V depending on the state of affairs. For example, a MacBook Pro USB-C charger will output 20V to charge the battery. When the battery is fully charged, and the MacBook is off, the USB-C charger will drib the output voltage to 5V.

In that location is no indicator lite on the USB-C charger connector to tell you what is going on. But the principle of the MacBook battery charging system is the same, although the communications between the USB-C charger and the SMC are much more complicated.

More for advanced readers: MacBook charging circuit discussion &  MacBook power-on sequences

Armed with this noesis, you are set to fix the Mac battery not charging problem at present.

iv. Fix MacBook not charging problem step-by-pace

Many factors could cause the MacBook battery not charging issue. Depending on the cause of the MacBook Pro or MacBook Air non charging upshot, the corresponding solution varies from easy to hard. We will discuss the easy solutions first and the most difficult i at the finish. Some hardware-related bug crave specific equipment and(or) spare parts. At the outset of each section, we will mention the difficulty level of the set up and equipment and(or) spare parts required for the repair. And then you lot can estimate your successful rate based on your skill. Good luck!

iv.one Cheque charger output voltage

Difficulty level: Beginner

Spare function required: Spare charger will help

If your MacBook charger is non working, of class it can't accuse the bombardment. So you lot need to brand sure the charger is working fine.

First, you demand to make sure that the ability outlet is ok. Yous can plug in a phone charger or a lamp to the power outlet, or plug in your MagSafe charger to another ability socket. This simple step lets you know that the power outlet is working or not.

Don't forget to check the ability string connection on the charger. The Apple tree adapter consists of two parts: the MagSafe charger and the removable ability cord. Make sure y'all insert the power cord to the MagSafe firmly.

Side by side, inspect both the input and output cable of the charger carefully, starting at one finish and work your way through until the other finish. Expect out for whatsoever fraying or tears in the cable. If at that place are any flaws like to the ones mentioned, this is probable to be the trouble. Replace the charger or endeavour some other available charger. Believe or not, these elementary checks ofttimes set the MacBook battery not charging upshot.

When you use a spare charger to exam the MacBook, beware that there are a few types of MagSafe chargers for different models of Mac laptops. The output voltages are14.5V for MacBook Airs, 16.5V and 18.5V for MacBook Pro, 20V for 15" MacBook Pro with retina screen. The basic rule is that the higher-voltage (therefore higher-power) charger can replace the lower-voltage charger.

In fact, Apple tree uses the same charging IC fleck (ISL6259) on the logic board from 2008 to 2015 to handle dissimilar types of MagSafe chargers. This IC chip volition automatically produce the correct voltage to power your MacBook and charge the bombardment. And so a higher-voltage charger will not harm your MacBook. Of class, when yous buy a replacement charger, buy the same type of your original one.

Too, the MagSafe i and MagSafe 2 chargers are not exchangeable equally the size of the connectors are slightly different.

If your MacBook uses Magsafe charger, as long every bit you lot can the green lite or orange calorie-free on the Magsafe connector, the MacBook charger is working fine.

The MacBook USB-C charger is smarter. Your MacBook volition automatically negotiate a suitable voltage output (5V, 14.5V and 20V) from the USB-C charger. You don't have to worry about the charger blazon, equally long every bit the charger has the capability to power the  MacBook.

If your MacBook uses a USB-C charger, you tin buy a minor USB-C ability delivery tester to monitor the behaviour of the USB-C charger shown as below. It tin can provide information including output voltage, output current and charger temperature. If you become 14.5V from a MacBook Air USB-C charger or 20V from a MacBook Pro charger, the charger is working fine. The photograph beneath shows the USB-C charger is delivering  power of 20.3V and 0.20A to the MacBook Pro.

4.2 Check charging port and Magsafe connector

Difficulty level: Beginner

Spare function required: None

Inspect the charging port on the MacBook and the MagSafe connector for debris and burned marks. The port and the connector rely on their potent magnetic allure to hold them together. The charging port tends to attract small metal items such every bit staples and paper clips. These strange objects foreclose the connector from shut contact with the charging port. The connector could be very warm due to the extra resistor created by the loose contact. In an extreme case, you even tin see the electric sparks. If you lot find burn marks on the charging port or the connector, you need to clean them or supersede them as soon every bit possible before they cause more damages.

If debris is found in the charging port, you tin can use a toothpick or a pair of metal tweezers to get it from the port. There is no ability voltage present on the 4 power-pins of the charging port.  The reverse-current protection gate (transistor) on the logic lath prevents the battery power reverse to the port. Yous won't accidentally short the circuit by using a metal tool to practice the cleaning job.

Pay attention to the center pivot of the charging port. Make sure there is no film covering the pin. The SMC uses this pin to communicate with the MagSafe charger. Any thin pic will block the electronic transmission, and you won't get the light-green or orange light fifty-fifty though both your MacBook and MagSafe are working. Use a small sharp pocketknife to clean the pins then finish up with cotton buds with 95% alcohol.

USB-C ports and plugs are too subject to clay. You can apply cotton and alcohol to clean them. Remember to remove the charger from the power outlet before you clean the connectors.

four.3 Reset SMC chip

Difficulty level: Beginner

Spare office required: None

The System Management Controller (SMC) controls the process of MacBook battery charging. If the SMC somehow has incorrect data of the MagSafe charger or the MacBook battery, the charger volition charge the battery very slowly or even non charge at all.

Apple started to use not-removable batteries in all MacBook models from 2008. Follow these steps to reset the SMC on a MacBook with non-removable battery:

1. Concord the ability button for at least five seconds until the MacBook turns off.
2. Connect the MagSafe charger, concord Shift-Control-Choice on the left-paw side keyboard and the power button simultaneously for x seconds.
3. Release all the keys.
4. Press the power button to turn on your Mac. Now yous have successfully reset the SMC.

Resetting the SMC on MacBooks with removable-batteries is unproblematic.

1. Agree the ability button for at least 5 seconds until the MacBook turns off.
2. Remove the ability adaptor and the battery from the MacBook.
3. Concur the power button key for 5 seconds to discharge any remaining electric energy in the capacitors of the SMC circuit. Alternatively, you can wait for a few minutes until the capacitors discharge naturally.
4. Re-install the battery back to your MacBook. At present you have successfully reset the SMC.

If resetting the SMC cannot solve your MacBook won't charge problem, reset the PRAM every bit discussed below.

four.iv Reset non-volatile random-admission retention (NVRAM)

Difficulty level: Beginner

Spare part required: None

NVRAM contains user-divers data such as screen brightness, keyboard backlight setting and sound volume setting. If this information is corrupted, your MacBook won't charge the battery or charge extremely deadening.

To reset the NVRAM, follow these steps:

1. Agree the power button for at least v seconds until the MacBook turns off.
2. Press the power push button to turn on the MacBook.
3. As before long as you hear the chime or see any calorie-free on the screen, hold Control-Pick-R-P four keys simultaneously until the MacBook restarts.
4. Release all the four keys.
5. After reboot, yous have reset the NVRAM.

If you nonetheless have the MacBook not charging upshot, motility on to the side by side level – hardware faults troubleshooting.

4.5 Cheque battery connector

Difficulty level: Basic

Spare office required: None

All pre-2016 MacBooks utilise ix-pin connectors to connect the batteries to the logic boards. Pivot half dozen is used for bombardment detection. When you connect a battery to the logic lath, this pin volition send a betoken to the battery internal "smart" circuit to plow on the "safety switch" called MOSFET. Therefore the electric current can catamenia in and flow out of the bombardment freely. This prophylactic blueprint prevents accidentally shorting the battery terminals and causing damage to the battery or even fire.

Also, SMC uses pin four and five to communicate with the battery. As all these pins 4, 5 and 6 comport depression-voltage electronic signals, any of them slightly loose contact volition cause MacBook not charging.

Brand sure in that location is no dirt or liquid on the connector and socket. Use cotton buds with at least 95% booze to make clean the pins and reconnect the connector firmly.

4.vi Supersede the faulty battery

Difficulty level: Basic

Spare role required: Battery for your MacBook model

The SMC uses a pair of data lines chosen SM-jitney to communicate with the battery. SMC as well uses current-sensing circuits to monitor the real-time electric current coming in or out of the battery. Based on this data, your MacBook displays the bombardment info in the notifications section.

At that place are five battery notifications:

1. Normal
2. Service Battery
3. Supersede Soon
4. Replace Now
5. No Battery Bachelor

Apple's document has only defined the "Normal" and "Service Battery" messages, leading to a lot of misunderstanding fifty-fifty misleading data of "Supervene upon Before long" and "Replace Now" messages. We will clarify these letters here.

"Normal" means your battery is fine. Your battery retains more than eighty% of the original chapters.

"Service Battery" means the battery has degraded to less than eighty% of the original capacity. Normally, the bombardment notwithstanding can terminal for two or three hours of normal usage. You lot may choose to supercede the bombardment only it is not urgent. The battery could last for a year or two if you connect your MacBook to the charger well-nigh of the fourth dimension to reduce battery usage.

"Supersede Soon" means y'all need to adjust a battery replacement soon. Apple has not specified the criteria of this bulletin. Our test data shows that this bulletin ways your battery retains less than nearly 50% of the original capacity. If you even so utilize the battery, keep an eye on it and make sure the bombardment is not bloated. Below is a swollen battery in a 13" MacBook Pro. An inflated bombardment volition put pressure on the case, touchpad and even the logic board.

If y'all discover that your touchpad cracks or pops up, as shown in the photograph below, you nigh likely have an expanded battery. You need to replace the battery immediately to prevent more damage.

"Replace At present" means that the SMC still can communicate with the bombardment, but very piddling or even no electric current can catamenia in or out of the battery. If yous disconnect the charger, the MacBook will shut off at once. The battery finally comes to the end of its life.

"No Battery Bachelor" with a cross mark on the battery icon every bit on the photo below:

It ways the SMC cannot communicate with the bombardment at all. Your battery is either completely dead or non connected to the logic lath properly. Usually, replacing the battery tin can solve the problem. But from fourth dimension to time even when you replace the bombardment, you still get the "No Bombardment Available" message. This symptom is a strong indication that your logic lath is faulty. Yous need to get your logic board repaired to solve the MacBook not charging problem.

If your bombardment is faulty, y'all tin can become the battery replaced past a service provider or supercede the battery yourself.  When you order the bombardment online, quote the battery model instead of the MacBook model to ensure y'all will get the right bombardment for your MacBook. For instance, fifteen" A1398 MacBook Pro 2012 uses battery model A1417.

When you supplant the MacBook bombardment yourself, utilize your fingernail or a plastic stick to remove the bombardment connector from the logic board. Never use a metal screwdriver. Otherwise, you may brusque circuit the battery or even worse, destroy the SMC by sending the 12V battery power directly to it.

The battery is attached to the MacBook case by screws in Pre-2013 MacBook Pro and Pre-2018 MacBook Air. You simply remove the screws and disconnect the battery connector from the logic board. If you purchase replacement batteries online, almost of them come with a handy screwdriver.

Apple chooses to glue the batteries to the MacBook example in 2013 onwards MacBook Pros and 2018 onwards MacBook Airs. Removing the glued battery from the MacBook instance is a bit difficult for beginners. Pay attention to the dedicated logic board. You don't want to knock off some chips on the logic lath and destroy it.

The battery connection in newer MacBooks with USB-C charging ports is different. The ability lines and data communication lines are no longer on the same connector. Instead, the ability lines ("+" and "-" terminals) are connected to the logic board secured by a T-5 spiral to provide better contacts. The data lines are connected to the logic board via a flex cable.

The correct procedure to remove this blazon of battery is crucial. You need to remove the flex cable from the logic board first. Then use a T-5 screwdriver to remove the screw and disconnect the power terminals. One time you remove the data flex cable, the smart bombardment volition plow off the "safety switch" inside the battery and there will be no power on the power terminals.

If the information flex cable is not working due to loose contact or liquid harm, you will get the "No Bombardment Available" message.

Information technology-Tech Online is a leading Mac repair specialist in Australia. We are more than happy to help you if yous cannot fix the problems yourself. We offer competitive prices for MacBook battery replacement. Please contact us . Our experienced staff will call yous to assess your state of affairs and provide a gratis quote for yous.

4.7 Cheque battery indicator circuit

Difficulty level: Basic

Spare part required: None

The pre-2013 MacBook Pro comes with a battery condition indicator. You can push button the button to run across how much percentage the bombardment retains the power. This indicator shares the same excursion with which the SMC uses to communicate with the battery. If the indicator is faulty, especially later on being exposed to water, the SMC cannot talk to the bombardment, therefore reports no battery institute.

Fixing this trouble is piece of cake. You tin can supercede the indicator, or simply unplug the indicator cable if y'all determine not to utilize the indicator function any more than.

4.8 Bank check faulty DC-in Lath

Difficulty level: Intermediate

Spare part:  MacBook Pro DC-in lath

The battery on MacBook Pro non charging could exist caused past a failed DC-IN board in the Pre 2013 Mac. The SMC uses the centre pivot (pin three) to talk to the MagSafe charger. At that place is a diode on the  DC-IN board connecting pin three to the ground to protect the SMC circuit.

If there is a higher voltage accidentally applied to pin three, for instance, ability surge or pin 2 (xvi.5V – 18.5V) shorted to pin 3, the diode will short this high voltage to the ground to prevent the dedicated SMC being damaged.

If the diode has been damaged, the SMC cannot talk to the MagSafe charger so you won't get the green light. Of class, your MacBook won't accuse the battery as there is no power coming from the charger.

Fixing the problem is like shooting fish in a barrel. You can buy a DC board online for a few dollars. Depending on the MacBook model, y'all may demand to remove the logic board to disconnect the DC board cable.

If you need to remove the logic board, pay attention to the fan connector. The fan connector is very like shooting fish in a barrel to peel off. Repairing the fan connector requires micro-soldering skill and adds extra toll to your repair pecker.

You lot even can remove the diode, and the DC board will piece of work once more. But bear in heed that at that place is no protection to your SMC excursion in instance a power surge occurs.

four.9 Supervene upon faulty I/O board cablevision

Difficulty level: Intermediate

Spare part:  MacBook I/O board cable

There is a cablevision connecting the logic board to the I/O board. The SMC uses the "one-wired" circuit to talk to the MagSafe charger. This "one-wired" signal needs to pass the cable to the I/O board and finally reaches the charger.

If the cable is loose, the "one-wired" signal will non pass to the charger so you won't go the dark-green light on the charger connector and your MacBook won't charge the battery.

Remove the cable,  make clean the cable and two connectors on the logic board and the I/O board with a toothbrush and  95% alcohol. Call up the cable direction. If you connect the cablevision reserved, you may damage the MacBook.

The cable is prone to liquid damage. If y'all spill h2o on your MacBook Air correct before you get the MacBook not charging outcome, you most likely have a corroded cable and (or) connectors.

You can get the I/O board cable for a few dollars online. If your I/O lath is faulty, y'all also can get it for less than fifty bucks.

4.10 Repair the faulty reverse-protection circuit

Difficulty level: Advanced

Equipment required: Hot air gun rework station

If you lot connect an Apple original MagSafe charger to the MacBook, you lot can't see any green or orange lite on the connector. Merely if you lot plug in a tertiary-party charger to the MacBook, you tin can run across the dark-green or orangish light and your MacBook battery is charging the battery perfectly. This unique symptom indicates that y'all have a faulty reverse-protection circuit on the logic board.

The reverse-electric current protection excursion is designed to forbid the internal battery ability "reverse" out from the bombardment to the charger. If the reverse-current protection circuit has current leakage, fifty-fifty as little as a few milliamps, the original MagSafe charger volition discover the leakage, therefore, shut off the output.

On the other hand, the tertiary-party charger has no leakage detection office; therefore, go on to output every bit usual.

Now you have ii options. You can keep using the third-party charger every bit the leakage does non bear on the performance of your MacBook. The 2nd pick is to supervene upon the reverse-current protection MOSFET. You demand a hot air gun rework station to perform the task.

5. Sympathise the principle of MacBook battery charging circuit

We are going to await at some example studies at good-level.  Fully understanding the principle of the MacBook charging circuit is the primal to success. Here we take  MacBook Pro schematics 820-4924A for written report.

File name : MacBook-Pro-2015-Battery-connector.pdf

File name : MacBook-Pro-2015-Charging-excursion.pdf

1. When a battery is connected to the logic board, a 10KΩ resistor R7050 is connected to the battery connector J7050 pivot 15. The smart battery internal circuit detects the presence of the 10KΩ resistor, then opens the bombardment internal MOSFET to output the bombardment voltage. In other words, the battery output will remain close unless a 10KΩ resistor is detected. This is the condom feature of the smart battery.
2. The bombardment voltage PPVBAT_G3H_CONN is nigh x-12.6V depending on whether the battery is fully charged or not. PPVBAT_G3H_CONN passes the internal diode of Q7155, charging current sensing resistor R7150, fuse F7140 and becomes PPBUS_G3H power rail.
3. At present we take the PPBUS_G3H power track. Comport in mind that this voltage is passed from the diode inside the MOSFET Q7155. Q7155 is not open up yet. So at this moment, this temperate PPBUS_G3H is a "weak" ability rail and only can provide a very small-scale amount of current. This is a slap-up safety feature of Apple logic board design. Information technology prevents the bombardment from exposing due to overheating if there is a curt on the logic board. This temperate power track is powerful enough to power a PMIC to create an always-on power rail PP3V42_G3H.
4. The PP3V42_G3H power track will power the Organization Management Controller (SMC) and power management IC U7100. SMC volition read the code stored in the chip inside the battery via a pair of SMBus: SMBUS_BATT_SCL and SMBUS_BATT_SDA. This code contains information such equally bombardment voltage, charging status, battery capacity, charging circle counts, temperature and so on.
5. If the battery cheque is ok and it has plenty power to power the system, SMC will communicate with the charging PMIC U7100 via a pair of SMBUS: SMBUS SMBUS_CHGR_SCL and SMBUS_CHGR_SDA. And so U7100 volition output CHGR_BGATE to open MOSFET Q7155. At present we have a stable, "total power" PPBUS_G3H power rail fix for apply past the laptop.
6. When we printing the ability button on the keyboard, the SMC will power up the Apple laptop using the battery forth.
7. When a power adaptor is connected to the MacBook, U7100 will create its own PPBUS_G3H from the power adaptor. U7100 outputs CHGR_BGATE to control the Q7155 to accomplish battery charging or discharging according to the bombardment condition and the applications nosotros are running on the laptop. All these functions are governed past the SMC.

6. Advanced MacBook repair (bombardment not charging) - case study

Difficulty level: Expert

Equipment required: Hot air gun rework station, multimeter

This is a xiii" MacBook Pro 2015 with retina screen. The laptop works fine when a  charger is continued but shuts down immediately when the charge is removed. A "service battery" message is displayed on the notification section and there is an orange lite on the charger connector. The client said the laptop battery had been replaced by some other computer store merely the laptop is withal non charging. Initial inspection shows no bear witness of h2o harm or corrosion.

Connect the MacBook to our metered ability supply. The current drawn from the ability supply is 0.027A in standby mode. Supersede the battery with a known working bombardment. The electric current drawn is still 0.027A. This confirms that the problem is in the logic board. How practise we ready it?

Nosotros remove the logic board from the example and inspect it under a microscope. There is no show of liquid damaged at all. The schematics for this MacBook Pro is 820-4924A.

1. Measure battery connector J7050. The figures of pin 13 and xiv  SMBUS clock line and data line are 0.508 and 0.509 respectively in diode style. It means the bombardment advice bus to SMC should be fine. Measure pin 15 battery detection SYS_DETECT_L. The effigy is 9.viii KΩ. Information technology matches the R7050 figure on the schematics. So the bombardment detection circuit should also be fine.
2. Inspect U7100 charging circuit PMIC (Ability Management Integrated Circuit). There are no burned marks or burned components. Measure the value of the resistors between U7100 pin 27 and 28 CHGR_CSI_R. The figure is 22Ω, ok. Measure the value of the resistors between pin 17 and xviii  CHGR_CSO. The figure is two.9Ω, ok. The charging excursion seems ok.
3. Measure Q7155  MOSFET in diode mode. Pin 5 to 3 is 0.472, ok. Pin iii to 5 is an open line, very expert. Both pivot 5 and pin iii to pin one are all open line, splendid. All these measurements indicate the Q7155 is working fine.
4. There is no obvious faulty component found. This logic board is not easy to set up. We have to rely on intelligent guesses based on by experience – the "endeavor and error" arroyo.  The U7100 (charging circuit power management IC) is the beginning suspect. Let'southward replace it. The battery is still not charging after replacing U7100. We accept only killed an innocent charging chip.
5. The second suspect is Q7155. This MOSFET is used to control the battery charging electric current. Let's supersede it. The problem remains afterward replacing Q7155. We have just killed some other innocent scrap. This guess-by-experience method does not work in this case, plainly.  We have to stop this problem-solving arroyo before the repair job turns into a nightmare.
6. It is time to rethink our strategies. It is hard to go the charging circuit to accuse the bombardment in this instance, but we may work the other style around. We may use a expert battery alone to ability the laptop without connecting to the power adaptor, so we tin follow the bombardment discharging current period to pinpoint the faulty components. Let's do it.
7. Connect the logic lath to a skillful working society battery and measure the voltage of Q7155. The voltage on pivot v and pin 3 drops from 12.4V to 0V and keeps repeating. The voltage on pivot 4 drops from five.2V to 0V and repeats in a circle. There is no shorted circuit on pin five, pin 3 and pin 4. This measurement issue confirms that the Q7155 MOSFET is working perfectly. For some reason, it opens for one or ii seconds so closes.  It is why the voltage rises up to12.4V and then drops to 0V repeatedly. We have found the trouble now, merely why did the Q7155 non remain open?
8. Q7155 pivot five connects to the bombardment positive terminal straight. Dropping voltage in pin 5 means the battery is cut the output voltage past itself. If the battery is good, and in that location are no brusk circuits on the load side, then the only matter that can brand the battery shut off by itself is the battery detection circuit. This circuit is very unproblematic, consisting of only one 10KΩ resistor R7050.
9. We measured this resistor R7050 an hour agone and the effigy was 9.8KΩ. Permit's measure out information technology once more even though it even so looks good with no sign of damage. This time the figure is five.9KΩ. This resistor has an intermittent fault! This intermittent error made u.s. waste ane hour and kill ii innocent chips. If the resistor remains at v.9KΩ all the fourth dimension, we could take fixed the problem in five minutes. The intermittent faults are the virtually difficult faults to deal with.
10. Supplant R7050 with a proficient 10KΩ resistor and nosotros get a working laptop.

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Source: https://www.it-tech.com.au/how-to-fix-macbook-battery-not-charging-issue/

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