The above image shows the inside of a typical mobile charger. These chargers can burn anytime and then they need to be replaced or repaired. This tutorial is about how to repair mobile charger circuit.
Fortunately the mobile charger repair process isn't much hard.
As there are few components to be checked and needs to be replaced if the charger is dead.
Detecting the faults in charger circuit
Typical faults could be like below,
- Bent or broken charger pin
- Broken or damaged connecting wires
- Blown up resistors
- Faulty transistors
- Blown up electrolytic capacitors
You should have a little knowledge about the mobile charger circuit diagram, it could be helpful to detect faults easily.
Mobile charger repairing tips
The common things are usually burns/cuts in the transistor, the 1/2 watt resistor in power mains line, and occasionally few of the 1/4 watt resistors.
In this particular case the transistor was blown up, note that the board had 120A transistor. And we can replace it by a 13001 transistor easily. You can get two 13001 transistors from small (upto 11 watt) broken CFL boards.
Also note that the pinout of 120A and 13001 is mirrored. You need to insert it in the PCB rotated 180 degree.
In my case case, one 33 Ohms resistor was burnt out, and replacing it made the charger work again.
Yeah. Now the charger works, you can see the the LED is glowing.
Sometimes the electrolytic capacitors are also dead, you can find the bad capacitors by inspecting damages on those capacitors of the charger circuit. Usually you can see that the electrolytic capacitor's vents are blown-up.
You can detect bad resistors by inspecting the charred and blackened resistors or with a multimeter. You may also need to replace some of them to repair mobile charger circuit.
Now you just need to attach the output wire again and cover it up.
please send me working of this circuit with diagram
vilas khare says
The brain which you having is a god gift and I appreciate your knowledge considering your age. At present I am running 57 and having lot of interest in Electronics project ( hobby or very small budget ) but I have not appeared any electronic / electrical course only I know the diagramme and spare parts value etc. On this knowledge I am spending my spare time in repairing electronics / electrical items. Can you send me detail diagramme with test point of Emergency Light which works on 6 volt battery ( 2 tubes / one tube ) .
Thanks and awaiting your reply.
harish naik says
could you pls tell me how to replace burnt transformer to a new one? old transformer has neither mentioned voltage nor current raiting on it
siva gobi says
dear sir how to test pusle transformer is good or not by using multimeter and how to choose pulse transformer for different power supply circuits
jitender saini says
sir my charger led is fluctuated hw we can find the fault in it plz reply nd send me the information hw charger circuit work
raj kumar gope says
Dear Sir,can you help me to find aprox price for pcb with components used in mobile charger,
Manish Ojha says
Sir, I am facing a problem in the above chager TR 13001 is used and out put voltage is 5.0+ , when we use this charger with branded mobile it works ok , but when connected with Karbonn or any chinese mobile , the mobile functions does not work while charging. I tries and found that the voltage is kept 4.2-4.7V the mobile work and if the voltage is 4.7-60 it does not works. please guide.
Rodrigo Barros says
These tips are very good, you are to be congratulated.
dinesh choudhary says
dear sir my.phone charger was damage what can.l do. give me trips to repair.in hindi language message me at my phone please
l was poor l don't have money so please help
Dear Dinesh, please go to your friend who can repair mobile chargers, ask him/her to help.
Never mind, "l was poor l don’t have money" I don't think so.
My mobile charger is giving 5v voltage but not giving any apmere...almost zero..what can be the reason behind it?
I am trying to repair a charger whose resistor was blown probably due to short circuit or sparking at switch. I changed the blown resistor with 80k. The charger worked, but for 1 second it was on and another second it was off. Where is the error please help.
Nice article, 1 yr ago still valid.
I am also an hobbisty will check iyt this site again.
Can I do something? There is some topic i can write sbout for you?
ABHIJIT AGARWALA says
I have a mobile charger with half wave rectifier. A few days ago, its electrolytic capacitor was blown out, which was replaced along with some resistors and zener diod of 6.2 volt. But, the output voltage is very low only some milliamperes. Please give suggestions.
check for any shorts or leakage of output capacitor.