MagSafe repair. Replacing a cable with a magnetic connector

Mechanical damage is usually revealed by external inspection. In the case of our power supply, the problem arose with the cable at the base of the magnetic connector. If the cable looks intact on the outside, it means there may be damage inside the insulation or connector.

Be careful and try not to use a faulty power supply, this can be dangerous for your laptop and your health!

Let's start replacing the cable with a new one. To do this, you will need to disassemble the power supply and replace the old cable with a new one by re-soldering it.

Step 2 - Disassembling the Power Supply

We open the brackets designed for winding the cable when transporting the unit. We insert the pliers as shown in the illustration and open them with a little force until the halves of the housing begin to separate from each other. We repeat the procedure on the other side.

Step 3 - Preparing the cable for desoldering

Step 4 - Preparing the cable for desoldering

Step 5 - Cable Cutting

Step 6 - Soldering the Cable

Step 7 - Assembling the Power Supply

For convenience, we used a Spudger tool to apply glue to one of the halves of the block.

New original charger for MacBook - MagSafe 1 and MagSafe 2 can last for a long time. The most vulnerable point of this Apple laptop power supply is the cable.

They often bring us fully working MacBook chargers with a frayed white cable and ask us to change the cable. Until recently, a separate cable was not available for sale.

Now we can please owners of excellent laptops MacBook new service - replacement of the MagSafe cable for charging the MacBook.

If the spare part is available, you will have to wait about an hour.

Now let’s compare what is better, repairing an old charger or buying a new one?

New original MagSafe charger for MacBook Air and Pro will cost about 4500-5500 rubles.

New Chinese fake Charging a MacBook will cost slightly more than replacing the MagSafe cable.

But what is the best way to replace the wire versus buying a Chinese copy?

The fact is that copies of chargers have a simplified circuit that can damage your MacBook, and as a result, repairing the laptop will cost a pretty penny - from 5,000 rubles to 20,000 rubles.

There were also cases when the Chinese charger charged more slowly, damaged the battery, and even caused the touchpad to press spontaneously.

As you can see, it’s better not to take risks and restore the original charger.

Mechanical damage is usually revealed by external inspection. In the case of our power supply, the problem arose with the cable at the base of the magnetic connector. If the cable looks intact on the outside, it means there may be damage inside the insulation or connector.

Be careful and try not to use a faulty power supply, this can be dangerous for your laptop and your health!

Let's start replacing the cable with a new one. To do this, you will need to disassemble the power supply and replace the old cable with a new one by re-soldering.

Step 2 - Disassembling the Power Supply

We open the brackets designed for winding the cable when transporting the unit. We insert the pliers as shown in the illustration and open them with a little force until the halves of the housing begin to separate from each other. We repeat the procedure on the other side. Next, open the case completely.

Step 3 - Preparing the cable for desoldering

Step 4 - Preparing the cable for desoldering

Step 5 - Cable Cutting

Step 6 - Soldering the Cable

Black wire - to blue
White wire - to brown

Step 7 - Using Heat Shrink

Remember to place the tube on the wire before soldering.

Step 8 - Shrinking the Conduit

Step 9 - Preparing the block for assembly

If you find that your Macbook Pro's battery can no longer be charged from the original adapter, do not rush to poke it with a soldering iron. As stupid as it may sound, the first thing to do is:

1. make sure the contact in the socket is reliable (do not use a broken one);

2. make sure that there is power in the outlet (plug another, known working device into it);

3. check that the laptop’s power socket is not filled with foreign objects (usually food crumbs, compressed dust balls and other insects get there);

4. Carefully inspect the yellow contacts of the connector. They should not be burnt, blackened, or oxidized. When you try to push them in, the pins should come back without jamming. It is advisable not to scratch the gold-plated coating again;

5. make sure that the cord from the adapter to the connector does not have mechanical damage, creases, no exposed wires sticking out from under the insulation, no office chairs running over it, etc. You can easily replace a damaged wire with your own hands with any other appropriate cross-section. In MacBooks, there are only two wires from the power supply to the Magsafe 2 connector:

If you are a very lucky person, simply unplugging the adapter for a few minutes can save you. It happens that, due to a power surge in the network, the charger goes into protection and needs time to think about the blocking being reset.

Sometimes, when you connect the adapter to a Macbook, the charging indicator does not light up, but in fact it is charging. The fact is that required indicator(orange or green) lights up upon command from the SMC system management controller located in the MacBook. Sometimes, due to accumulated errors, the SMC begins to fail and then resetting the controller helps.

To do this, you need to connect the adapter to a completely switched off (not sleeping, namely switched off) MacBook, press the key combination Shift+Control+Option and, without releasing them, press Power. Then, simultaneously releasing all the buttons, turn on the laptop with the controller reset.

If all else fails, you will have to make a friend with exactly the same MacBook and quietly swap chargers with him and try to connect to his charger. It is not necessary that your friend has exactly the same adapter - a more powerful one will also work. The main thing here is that the connectors match. [Comment : According to one of the comments to this article, a less powerful power supply will also be suitable for testing]

If your MacBook battery does not charge with your charger, but when you connect someone else’s charger everything starts working as it should, then your charger is broken. Your cap. The bravest ones can tell their wife that the purchase of a mink coat is canceled again, since the MacBook is more important. The rest will have to repair the adapter themselves.

I happened to have a faulty power supply with a MagSafe 2 connector and a power of 60 W, so the following will mostly be true for this adapter. This charger was included with 13-inch MacBook Pro models with Retina display:

• MD212, MD213 (late 2012)
• MD212, ME662 (early 2013)
• ME864, ME865, ME866 (late 2013)
• MGX72, MGX82, MGX92 (mid 2014)
• MF839, MF840, MF841, MF843 (early 2015);

Macbook Pro charging repair

Before you dig into the internals, it's useful to know how the charging process is initiated. You might be surprised, but Apple engineers managed to integrate microprocessor control even into such a simple device as a charger. Here are the key points:

1. operating voltage is 16.5 Volts. However, as long as the adapter is not connected to a load, its output has an open circuit voltage (about 3V) with a current limit of ~0.1 mA;
2. After connecting the connector to the MacBook, the adapter output is loaded with a calibrated resistive load, due to which the open circuit voltage drops to a level of ~1.7V. The 16-bit microcontroller in the charger detects this fact and after 1 second commands the output switches to output full voltage. Such difficulties allow you to avoid sparking and burning of the connector contacts when connecting the charger to the laptop;
3. when connecting too much load, as well as in the presence of a short circuit, the open circuit voltage will drop significantly below 1.7V and the turn-on command will not follow;
4. The Macbook Pro power connector contains a DS2413 microchip, which immediately after connecting to the MacBook begins exchanging information with the SMC controller via the 1-Wire protocol. The exchange takes place over a single-wire bus (middle contact of the connector). The charger tells the laptop information about itself, including its power and serial number. The laptop, if everything suits it, connects its internal circuits to the adapter and tells it the current operating mode, based on which one of the two LEDs in the connector lights up. The entire exchange of pleasantries takes less than 100 milliseconds;

Considering the above, it is unlikely that you will be able to charge your MacBook without native charging. It's also not possible to check the power supply without a MacBook.

Theoretically, for testing, you can connect a 39.41 kOhm resistor to the two extreme contacts of the Magsafe connector (which is not so easy to do, given the design of the connector). After a second, a voltage of 16.5 Volts should appear on the resistor. In this case, the indicator on the connector will not light up.

For those who don't know, the Apple Magsafe 2 power supply connector has the following pinout:

This clever design of the charging socket allows you to connect your Macbook without worrying about polarity.

Despite the fact that the original adapter has all kinds of foolproof protection built in, you should not treat it with disdain. The power of this power supply is enough to burn you with flames at the first opportunity, splash you with molten metal and scare the crap out of you... hiccups.

How to painlessly disassemble the adapter

To disassemble the charger from a Macbook you will have to use brute force, since the body halves are glued to each other. The most painless option is to use pliers as shown in this video:

I was able to disassemble the power supply from my Macbook Pro in 2-3 minutes (most of the time was spent finding a convenient stop for the pliers). After this, light traces of an autopsy still remain:

After the case is opened, you need to carefully inspect the printed circuit board to identify burnt tracks, charred resistors, swollen or leaking electrolytes and other anomalies.

The board will most likely be filled with some kind of compound; it needs to be carefully removed. And it would be nice not to tear off anything unnecessary.

It wouldn't hurt to immediately ring the 3.15A fuse. Here it is, in a brown case:

If the fuse is faulty, then this usually indicates a breakdown of either the diode bridge, or the power MOSFET, or both. These elements burn most often, since they bear the main load. They are very easy to find - they are located on a common radiator.

If knocked out field-effect transistor, it makes sense to check the low-resistance resistor in the source circuit and the entire snubber circuit (R5, R6, C3, C4, D2, two chokes FB1, FB2 and capacitor C7):

When repairing a Macbook power supply, it is strongly recommended to connect it to a 220V network through a 60-watt light bulb. This will prevent devastating consequences in the event of a short circuit in the circuit.

Be extremely careful! A high-voltage capacitor can maintain life-threatening voltage for a long time. I got caught once and it was extremely unpleasant.

If after replacing faulty elements the power supply does not start, then, alas, further repair of the charger Apple devices Magsafe 2 is not possible without an electrical circuit diagram.

By the way, the most reliable way to find out whether the circuit is working or not is to measure the voltage at the output electrolytes. On the working adapter there should be 16.5V:

Magsafe 2 adapter circuit (60 Watt)

Find schematic diagram Macbook power supply failed, so there was nothing left to do but copy it from printed circuit board. Here is the most interesting fragment:

As can be seen from the diagram, the charger is assembled according to the classic circuit of a single-cycle switching power supply. The heart of the converter is the DAP013F chip - a modern quasi-resonant controller that allows you to achieve high efficiency, low noise levels, and also implement protection against overload, overvoltage and overheating.

At the initial moment of time, after connecting the adapter to the socket, there is no voltage on winding turns 1-2; accordingly, the voltage at the gate of transistor Q33 is zero, and it is closed. At its drain, the voltage is equal to the operating voltage of the zener diode ZD34, which is supplied there from a full-wave rectifier formed by diodes D32, D34 and part of the power diode bridge BD1, through a chain of resistors R33, R42.

Transistor Q32 is open and capacitor C39 begins to charge from the same diode rectifier (via the circuit: R44 - ZD36 - Q32). The voltage from this capacitor is supplied to the 14th leg of the IC34 microcircuit, which, through its internal switch, is connected to pin 10 and, accordingly, to a 22 µF electrolytic capacitor C (we could not find its designation on the board). The initial charging current of this capacitor is limited to 300 μA, then, when the voltage across it reaches 0.7 V, the current increases to 3-6 mA.

When capacitor C reaches the startup voltage of the microcircuit (about 9V), the internal oscillator starts, pulses from the 9th pin of the microcircuit are sent to gate Q1, and the entire circuit comes to life.

From this moment on, the voltage of the IC34 microcircuit is supplied from capacitor C, the voltage on which is generated from winding 1-2 of the transformer through the rectifier diode D31. In this case, the internal switch of the microcircuit breaks the connection between the 14th and 10th pins.

Protection against excessive increase in output power is implemented using elements ZD31 - R41 - R55. When the voltage at the output of winding 1-2 increases above the breakdown voltage of the zener diode, a negative potential appears at the 1st pin of the microcircuit, which leads to a proportional decrease in the amplitude of the pulses at the 9th pin.

Overheating protection is implemented using an NTC31 thermistor connected to the 2nd pin of the microcircuit.

The 4th pin of the microcircuit is used to determine the moment of switching of the output switch at the points of minimum current.

The 6th pin of the microcircuit is designed to stabilize the output voltage of the adapter. In the chain feedback includes an optocoupler IC131, which provides galvanic isolation of the high-voltage and low-voltage parts of the adapter. If the voltage on the 6th leg drops below 0.8V, the converter switches to reduced power mode (25% of the rated power). For correct operation In this mode, capacitor C36 is required. To return to normal operation, the voltage on the 6th leg must rise above 1.4V.

The 7th leg of the microcircuit is connected to the current sensor R9 and if a certain threshold is exceeded, the operation of the converter is blocked. Capacitor C34 sets the time interval for the auto-recovery system after an overcurrent.

Pin 12 of the microcircuit is designed to protect the circuit from overvoltage. As soon as the voltage on this leg exceeds 3V, the microcircuit goes into blocking and will remain in this state until the voltage on capacitor C drops below the controller reset level (5V). To do this, you need to unplug the adapter from the network and wait a while.

It seems that this adapter does not use the overvoltage protection functionality built into the chip (in any case, I was not able to trace where resistor R53 is connected to). Apparently this role is assigned to transistor Q34, connected to the feedback circuit in parallel with optocoupler IC131. The transistor is controlled by voltage from winding 1-2 through a resistive divider R51-R50-R43 and in the event of, for example, an optocoupler malfunction, it will not allow the microcircuit to increase the converter voltage uncontrollably.

Thus, this 60-watt power adapter implements three-fold protection against exceeding the output voltage of permissible limits: an optocoupler in the feedback circuit, a Q34 transistor in the same circuit, and a ZD31 zener diode connected to the 1st leg of the microcircuit. Add here also protection against overheating and overcurrent (short circuit). It turns out to be a very reliable and safe charger for a MacBook.

In Chinese chargers, most of the protection systems are thrown away, and, in the interests of economy, there are no circuits for filtering RF interference and eliminating static electricity. And although these crafts are quite functional, you have to pay for their cheapness with a higher level of interference and an increased risk of failure of the laptop power board.

Now, having the diagram in front of your eyes and imagining how it should work, it will not be difficult to find and fix any malfunction.

In my case, the malfunction of the adapter was caused by an internal break in resistor R33, which is why transistor Q32 was always locked, voltage did not flow to the 14th leg of the controller, and accordingly, the voltage on the capacitor WITH could not reach the chip's turn-on level.

After soldering resistor R33, the microcircuit trigger circuit was restored and the circuit started working. I hope this article will help you fix the charger on your MacBook Pro.

To help you identify completely burnt-out elements, I am attaching an archive with photographs of the board in high resolution(37 photos, 122 MB).

And people dissected exactly the same charger, only with a power of 85 W. Interesting too.

If you need MacBook charging repair in Moscow, contact Yudu specialists. The technicians registered on our website will conduct computer diagnostics, determine the causes of the breakdown and quickly restore full operation of the charger. It can be repaired on the same day you call.

Yudu performers will fix any problem in a laptop with an apple logo. They will repair the power supply, charge controller, adapter and connector. Also, if necessary, they will replace the cable on the charger so that the MacBook Air begins to fully charge.

When to contact a service center

Service center services are required if:

• is happening fast discharge devices
• laptop won't charge
• moisture has entered the connector
• MacBook won't turn on

When MacBook Pro charging cannot be repaired, Yudu's performers will recommend purchasing a new charger. If the problem is in the MacBook itself, a specialist will carefully check all the parts that are responsible for charging the battery and repair the necessary elements.

The weak point of the MacBook Air is the cable. Over time, it frays at the joints. The integrity of the cable can be damaged mechanically. Supplying power through a damaged cable may cause problems with other parts of your Mac.

Have more modern models MacBook Air does not have such problems, since they have a built-in adapter. But after contact with moisture, it may stop working and you will need professional help.

When the first signs of inoperability of the original charger appear, seek help from specialists. They will match the adapter to your laptop model, since the MacBook Air and MacBook Pro 2013 have different adapters.

Cost of specialist services

Repairing a MacBook Pro charger in Moscow does not require large financial costs. This is a simple action that Yudu performers perform often. They will quickly and inexpensively eliminate all damage and consequences of exposure to moisture. As a result, you will receive a fully functioning MacBook that will turn on in a timely manner.

Why should you contact Yudu specialists?

Our site's technicians will repair the device and eliminate all faults that are discovered during diagnostics. Craftsmen registered with Yuda have been doing repairs for years Apple technology, so you can rest assured of their professionalism.

Cooperation with Yudu performers is beneficial because they:

• have all original components available
• renovating the whole the lineup Apple devices – MacBook Air, MacBook Pro 2013 and later models
• carry out computer diagnostics of the gadget
• carry out repair work before your eyes

Once the problem is fixed, the laptop will work perfectly, and rapid discharge will no longer complicate the operation process.

Order the services of Yudu specialists who will ideally repair your MacBook charging and will be able to return the laptop with the Apple logo to its previous functionality.