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A low quality laptop power supply was brought to me for repair. The rating of this laptop power supply is 19 volts and 3.42 amps. The customer was my friend and he works in the computer sales. Here is the information about it.
The reason I noticed it was a low quality one is by it weight. You will see later on that the inside of this laptop power supply will prove me right
As you can see in this photo, there is no standby light and therefore I had to open it to see what is wrong with this charger.Usually in a case like this, I usually think of bad output cable because I have seen it happen so many times. This time I believe it was a different case. Let the work begin
The moment I opened it, I saw this. As you can see in the photo, there are two soldering joints that are already loose. It was the ground pin and one of the capacitor legs pin. Soldering these two loose pins did not bring the charger back to life.
I have found two capacitors faulty.
The main capacitor which is 47uf/400 volts was bulged. I found the other one at the output of this power charger. I believe it was 470uf/35. Before I replaced these faulty capacitors I resoldered a lot of cold soldering joints on that board.
As you can see in this photo, the main capacitor is bulged and had to be replaced.
These are the two faulty capacitors that were replaced. The moment I replaced these two, look what happened.
I am sure you have noticed that I replaced the main capacitor with a higher rate one. As I mentioned before, it was 47uf/400 and I have replaced it with 68uf/450 volts capacitors. I have tested this laptop charger for almost an hour and it worked fine.
The reason I noticed it was a low quality one is by it weight. You will see later on that the inside of this laptop power supply will prove me right
As you can see in this photo, there is no standby light and therefore I had to open it to see what is wrong with this charger.Usually in a case like this, I usually think of bad output cable because I have seen it happen so many times. This time I believe it was a different case. Let the work begin
The moment I opened it, I saw this. As you can see in the photo, there are two soldering joints that are already loose. It was the ground pin and one of the capacitor legs pin. Soldering these two loose pins did not bring the charger back to life.
I have found two capacitors faulty.
The main capacitor which is 47uf/400 volts was bulged. I found the other one at the output of this power charger. I believe it was 470uf/35. Before I replaced these faulty capacitors I resoldered a lot of cold soldering joints on that board.
As you can see in this photo, the main capacitor is bulged and had to be replaced.
These are the two faulty capacitors that were replaced. The moment I replaced these two, look what happened.
I am sure you have noticed that I replaced the main capacitor with a higher rate one. As I mentioned before, it was 47uf/400 and I have replaced it with 68uf/450 volts capacitors. I have tested this laptop charger for almost an hour and it worked fine.