As a rule, the repair of such an inexpensive device is not economically viable.
Especially in non-poor countries. The average price is 5 dollars.
But it happens that there is no extra money, but there is time and spare parts.
There is no shop nearby. Circumstances do not allow. Then it's not about the price.
In my case, everything was simple - one of my two chargers broke Nokia AC-3E, friends brought a bag of broken chargers. Among them there were about a dozen branded Nokia chargers. It was a sin not to take it.
The search for the circuit did not lead to anything, so I took a similar one and remade it for AC-3E. A lot of chargers for mobile phones have been made according to a similar scheme. As a rule, the difference is not significant. Sometimes the ratings are changed, a little more or a little less elements, sometimes a charge indication is added. But basically the same thing.
That's why given description and the circuit will be useful for repair not only AC-3E.
The repair manual is simple and written for non-experts.
The scheme is clickable and of good quality. 
THEORY.
The device is a blocking generator operating in self-oscillating mode. It is powered by a half-wave rectifier (D1, C1) with a voltage of approximately +300 V. Resistor R1, R2 limits the starting current of the device and acts as a fuse. The blocking oscillator is based on a transistor MJE13005 and pulse transformer. Required element, the blocking oscillator is the circuit positive Feedback formed by winding 2 of the transformer, elements R5, R4 C2.
The 5v6 zener diode limits the voltage at the base of the MJE13005 transistor to within five volts.
Snubber chain D3, C4, R6 limit voltage surges on winding 1 of the transformer. At the moment the transistor turns off, these surges can exceed the supply voltage by several times, so the minimum allowable voltage of the capacitor C4 and diode D3 must be at least 1 kV.
PRACTICE.
1. Disassembly. Self-tapping screws holding the charger cover in this device have the shape of a triangular star. As a rule, there is no special screwdriver at hand, so you have to get out as best you can. I unscrewed it with a screwdriver, which during the operation itself sharpened under all sorts of crosses.
Sometimes chargers are assembled without bolts. In this case, the body halves are glued together. This indicates the low cost and quality of the device. Disassembling such a memory is a little more difficult. It is necessary to split the body with a non-sharp screwdriver, gently pressing on the junction of the halves.
2. External inspection of the board. More than 50% of defects can be detected precisely due to external examination. Burnt resistors, a darkened board will show you the location of the defect. A burst case, cracks on the board will indicate that the device was dropped. Chargers are operated in extreme conditions, so falls from everywhere are a common cause of failure.
In five out of a dozen memories that I had a chance to do, they were trite contacts are bent through which 220 volts are supplied to the board.
To fix it, just bend the contacts slightly towards the board.
To check the contacts are to blame or not, you can solder the power cord to the board and measure the output voltage - red and black wires.
3.
Broken cord at the output of the memory. It breaks as a rule at the plug itself or at the base of the charger. Especially for those who like to talk while charging the phone.
Called by the device. Insert the lead of a thin part into the center of the connector and measure the resistance of the wires.
4.
Transistor + resistors. If there is no visible damage, first of all you need to unsolder the transistor and ring it. It must be borne in mind that the transistor
MJE13005 base is on the right, but it happens the other way around. The transistor may be of a different type, in a different case. Let's say MJE13001 looks like a Soviet kt209 with a base on the left.
Instead, I put MJE13003. You can put a transistor from any burnt lamp - the housekeeper. In them, as a rule, the filament of the bulb itself burns out, and two high-voltage transistors remain intact.
5. The consequences of overvoltage. In the simplest case, they are expressed in short-circuited diode D1 and a broken resistor R1. In more complex cases, the MJE13005 transistor burns out and inflates the capacitor C1. All this elementary changes to the same or similar details.
In the last two cases, in addition to replacing burnt conductors, it will be necessary to check the resistors around the transistor. With a diagram, this will be easy to do.
The voltage on the battery was about 3.1 volts, which is less than the threshold after which some chargers recognize the battery and begin to charge it. Anyway, that's how it was with my Blackberry battery, which went too deep.
The LI-12B battery was brought back to life by charging with a small current, about 100 mA. For this, it was collected simple circuit. When the voltage on the battery reached 4.2 volts, I stopped the charge and checked the camera's performance. The camera started working and I began to think about how to repair the charger. https://website/
Repair charger LI-10C.
This is what it looked like when I got it Charger.
To disassemble the LI-10C charger, it was necessary to unscrew two self-tapping screws, one of which was under the sticker.
Checking the operation of the charger revealed the presence of short-circuited turns in the isolation transformer impulse block nutrition.
The pulse transformer turned out to be unrepairable, besides, I did not find a suitable ferrite core so that I could wind a new transformer.
On the picture printed circuit board charger. The arrow marks the transformer DS-4207 KT04044.
I decided it was already time to go to our radio market after the weekend, but then I remembered that I have a five-volt charging board for mobile phone.
I once bought this charger in a faulty condition for the sake of a plug case, so that a power supply for a radiotelephone, once designed for a mains voltage of 120 volts, could be placed in it.
To check the transformer, I had to first draw a diagram, and then replace all the burnt parts.
To my joy, the transformer turned out to be good, and it seemed to be just right in terms of dimensions.
Actually, all further repairs consisted in replacing the transformer.
If you look at a typical circuit for switching on the PWM driver chip of this FSDH0165 charger, you can see that the transformer from the circuit above is functionally not much different from the burned one.
Today many people use portable devices. The latter work autonomously, need periodic charging. For this, special power supplies are used to connect the device to the mains. The charger must charge the phone, player, netbook for certain time. If it does not cope with its functions, we are talking about a possible breakdown.
The charger can be replaced with a new one. This method is simple and affordable. But original device experts recommend repair. It is much more reliable than analogues and replicas on the market today. You will learn how to fix the charger with your own hands from the instructions below.
Device Diagnostics
The basis of competent repair has always been and remains high-quality diagnostics. It is important to determine the cause of the charging failure. There may be several of them. The most common: plug failure, board failure, wire failure. Most often, charges are thrown away for the latter reason. But a wire breakage is not a reason to spend money on a new device. This malfunction is easily fixable with your own hands.
Charging repair: stages
If the wire near the power supply is broken in the charger, you must perform the following steps:
- Disassemble the charger (unscrew the fixing bolts, remove the case).
- Cut off the broken wire, fix it with a knot in the charging case.
- Strip the ends of the wire.
- Unsolder the broken piece of wire remaining on the board (carefully so as not to overheat the sensitive element).
- Solder the stripped wire in place of the old wire.
- Test the device.
If the phone is charging, the power supply can be assembled. If not, the wire is most likely broken somewhere else. In this case, the easiest way is to replace it with a new one by attaching it to the block and plug.
If the plug itself is faulty, it is quite simply replaced with a new one. It is necessary to select an element of the appropriate format. The plug can be purchased from parts stores for mobile devices or use a part from another device of a similar type, purpose.
More serious damage to the charger is usually not repairable. If the board burned out, theoretically it can be replaced with a new one. But finding spare parts can be problematic. In this case, it is recommended to purchase a new charger.
Very often, equipment breakdowns are so elementary and easily fixable that sometimes you don’t even want to take on repairs, it’s not of interest, but you have to. Recently, a friend of mine turned to me for help, so he had not lived well before, and recently, due to the crisis, he also lost his job.
Shows universal charger type Frog for lithium batteries from phones with broken clamps on the clamping part, and asks if anything can be done. She says that they sat on it. My first thought was to offer him to throw it away and buy a new one, but after looking at his distressed face, he changed his mind and decided to help.
There were two new crocodiles in isolation, only the tip protruded, and it was decided to solder to the wires going to the antennae, and connect to the battery with crocodiles. I plugged the charger into the outlet to make sure that it worked at all, and my labors would not be in vain, and began to disassemble.
First, 2 screws were unscrewed, securing the antennae to the part pressing the battery, the antennae were intact. Often, during work, these antennae break off, and it becomes impossible to use, so I left the antennae in reserve. If someone does not know how to use such a charger, I will explain: we take lithium ion battery, from cell phone, cameras and other similar equipment. We combine the antennae of the charger, with its plus and minus contacts, they are signed on the battery, and press the battery to the charger body, due to the spring of the pressing part. The LED on the charger should light up, indicating that there is contact between the antennae and the battery contacts. For those who may need to send a similar charger, with a more serious breakdown, I will give one of the options for the circuit diagram:
Charger circuit
Let's return to our repair, having unscrewed two screws, dismantled the body of the frog. It remained to determine which of these wires going to the antennae is plus and which is minus. Such a check is rather conditional, because such chargers have, or automatic detection polarity, and then there are no buttons, or there is a polarity reversal button.
But still, I wanted to assemble it so that the red probe was a plus, and the black one was a minus. Then I removed the board and found a common wire connected to one of the wires, it was connected to the polygon on the board. It was decided to consider it as a minus. Then it was a matter of technique, beautiful wires were needed to connect with the wires coming from the antennae. I just had such wiring from the computer speaker. The speaker itself and the connector were cut off, I decided to take the length of the wires sufficient for convenient connection to the battery contacts.
Recently, I've got into the habit of following the aesthetics of the connections in the device, no matter if I make it for myself or for people, for money or for purely symbolic gratitude. Therefore, I bought myself heat shrinks with a margin, of different diameters, for all occasions, and decided to abandon the snot on the joints in the form of electrical tape. Which, by the way, not only looks ugly, but also strives to slide off the wire connection over time and expose it. What it is fraught with, I think no one needs to explain.
So here, too, before soldering the wires, I put two pieces of heat shrink on the wires, and after soldering I warmed up the lighters on the fire. It turned out to be a beautiful reliable isolation. By the way, in the West, judging by the insulation of LEDs and buttons, computer cases, they have long abandoned the use of electrical tape, and they pack everything that remains for long-term use only in heat shrink. Before soldering the wires, out of habit, I tied the wires in a knot so that it was impossible to pull out the wires with an effort. To do this, just the node, the size of which is larger than the hole into which the wire is passed in the charger case, will not allow.
It remains only to assemble the charger in the case and test it by plugging it into the network and connecting it with crocodiles to the battery contacts. Everything worked as it should, the LED began to flash, indicating that the battery was charging. And as it turned out, with the polarity and color of the crocodiles, when soldering the wires, I was not mistaken. Good luck with your repairs! The author of the article is AKV.
Increasingly, people are having problems with a charger failure, which leads to unpleasant consequences, as it becomes impossible to charge the phone if there is no other alternative to the charger. In today's article, we will look at all types of breakdowns and repair of the charger.
And so, to begin with, we will determine the main reasons for the failure of the charger, it can be:
- Breakage of the supply wire of the device;
- Damage to the charger unit;
- Broken contacts, connections or wires in a plug or power supply;
The most common cause of failure of the charger is a break in the internal wires or damage to the connections between the plug or block. In such cases, the device can be taken to service centers or repaired independently. In this article we will consider the second option, as an example we will use a charger with a thin plug from Nokia.
To repair the charger, we need:
- Ordinary multimeter;
- Knife for cutting wires;
- Soldering iron and solders;
- Insulating tape and heat shrink tubing, if available;
- A coil of thin copper wire for connecting contacts or damaged parts;
The first thing we will start is looking for damage in the wire or contact connections. It is quite easy to determine the place where the wire broke, this is facilitated by a non-standard color or a smaller diameter of the wire itself.
If it was not possible to visually determine the place of the break, then the damage may not be a wire break at all, but a defect in the connections between the device unit or the charging plug.
Getting Started with Charger Repair. First of all, we cut off the wire in the region of 7-10 cm from the plug, if the gap is not detected, we can reconnect the plug to the power supply. Therefore, it is not advisable to cut the wire close to the plug or power supply, because after that we will not be able to solder it back.
Next, we clean the wire from insulation (the one on the side of the power supply). We take a multimeter and set the maximum allowable voltage to 20V. (You can find out more about how to use a multimeter in). We connect the contacts of the multimeter to the broken and cleaned wires and insert the charger into the network.
If the multimeter shows any value, then there is no damage to the power supply and the wire. In our case, the multimeter showed 7V - this means that the power supply is working properly, since the nominal output voltage devices is equal to the same value.
We perform the same action with the charger plug. We clean the wire from insulation and insert a thin wire into the inside of the contact wire, this will be needed to accurately measure the nominal value of the plug with a multimeter.
In the multimeter, select the dialing mode and touch one end of the probe to one of the protected wires, and with the other, first to the plug, then to the inserted wire. If the multimeter emits sound signal, then this will mean that there is voltage between the plug and the wire and that the plug itself is working.
If the device has not issued sound alert, then it follows that the plug is defective and its contacts may be damaged. In such cases, you can go to the store and buy a new charger or replace only the plug, but you can also repair it, which we will do now.
If you have another working plug, you can replace it by simply soldering a new one to the old power supply, while it is important to observe the polarity, for this there is a color marking on each cord, you need to solder all the wires according to the corresponding colors.
But sometimes it happens that there is no color marking, in such cases you need to plug the charger into the network, and a new plug to the phone. Next, you need to connect all the wires of the plug to the wires charging block. If the phone goes into charging mode, then you did everything right. If not, then change the wire connections until the phone goes into charging mode.
After that, we proceed to soldering. If you have a heat shrink tube, then before soldering, we put it on one of the wires, after which we solder both ends, observing the polarity, after which we wrap the junction with electrical tape and put the heat shrink tube back on.
But if you do not have an additional plug, then you will have to repair the old one here. To do this, you will need to carefully remove the rubber coating from the old plug with a knife, while trying not to damage the connections of the plug itself.
After that, we check the performance of the plug. We turn on the charging unit in the network and connect the cord to the phone. If everything works, isolate all connections and attach a heat shrink tube to the plug. Then the charger is ready for use.
But it happens that when cutting the wire and checking the voltage, it turned out that it is absent, then in this case you will also have to cut the wire in front of the charging unit, stepping back about 7-10 cm. It is required to protect the wire coming out of the power supply from damage, after which it is necessary to measure the presence of the output voltage. If there is voltage, then this indicates the health of the charging unit.
In our case, it turned out that one conductor of the plug was broken. Visually it is difficult to identify. The best option maybe buying a new wire and soldering it in place of the old one.
In this case, you also need to observe the polarity, and also check the wire contacts before soldering by connecting the charging unit to the network and the plug to the phone. If the phone began to accumulate charge, then you can start soldering the wires, and then insulate them.
If the wire and plug of the charger are good, then the damage is most likely in the charging unit. Perhaps the problem may be in the breaking of contacts inside the charger. To fix the damage, you need to disassemble the charger unit and check all the wires and contacts for a break. If everything is in order with them, then the problem lies in the charger unit itself. At the same time, without having the skills of electrical engineering, you will not be able to repair the charging unit. In this case, you will have to buy a new charger or take the old one to a service center.
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