laptop charger adapter 65w Repair

Thread Starter

belcom10

Joined Aug 15, 2017
12
Have been following this site. please, i came here to solicit the assistance of concern member of this forum to repair my laptop adapter. i am learning electronics. i felt it is necessary for me to practice as it will help to know better.
i discovered that the big capacitor swollen , the led is not coming up.
 

AlbertHall

Joined Jun 4, 2014
12,345
If you are just beginning electronics repairing a switch mode power supply is not a good place to start. They are difficult and dangerous enough to repair when you have lots of experience repairing them. I speak as someone who spent years repairing them and supervising others repairing them.

That said, bulging capacitors are clearly defunct and need replacing. If you are lucky that may be the only fault. Did it blow a fuse?
 

Thread Starter

belcom10

Joined Aug 15, 2017
12
th
If you are just beginning electronics repairing a switch mode power supply is not a good place to start. They are difficult and dangerous enough to repair when you have lots of experience repairing them. I speak as someone who spent years repairing them and supervising others repairing them.

That said, bulging capacitors are clearly defunct and need replacing. If you are lucky that may be the only fault. Did it blow a fuse?
thanks for your response, no fuse blown
 

MrAl

Joined Jun 17, 2014
11,389
Hello,

Actually i repair everything i possibly can of my own stuff, but for this i have to recommend getting a new one off of a site like Amazon. You might find one for 10 dollars (USD) for example as i did just a few weeks ago when i needed one.

When the caps bulge that means they are shot, so you have to replace them. What happens is the capacitance goes down and the ESR goes up, and it's enough to stop it from turning on in many cases. I've done this in my computer power supply AND an LCD TV i have because it happened in both products over some time. It is always the low voltage electrolytics (5v, 12v, supplies etc.).
I would think replacing them would work, but in your photo i dont see any bulging. Take another pic maybe?

You do have to figure that if you buy the caps and it does not work, then you have to look for a new one anyway, so it's up to you. If it is successful, you will only save a few dollars but it is rewarding to fix it yourself too.

It amazes me how unreliable electrolytic caps can be when run near their full specifications.
 

Thread Starter

belcom10

Joined Aug 15, 2017
12
Hello,

Actually i repair everything i possibly can of my own stuff, but for this i have to recommend getting a new one off of a site like Amazon. You might find one for 10 dollars (USD) for example as i did just a few weeks ago when i needed one.

When the caps bulge that means they are shot, so you have to replace them. What happens is the capacitance goes down and the ESR goes up, and it's enough to stop it from turning on in many cases. I've done this in my computer power supply AND an LCD TV i have because it happened in both products over some time. It is always the low voltage electrolytics (5v, 12v, supplies etc.).
I would think replacing them would work, but in your photo i dont see any bulging. Take another pic maybe?

You do have to figure that if you buy the caps and it does not work, then you have to look for a new one anyway, so it's up to you. If it is successful, you will only save a few dollars but it is rewarding to fix it yourself too.

It amazes me how unreliable electrolytic caps can be when run near their full specifications.
 

notmellow

Joined Dec 13, 2017
1
Good evening,
I don't see any bulging, but i'll take your word on it. The best advice I can give you is don't spend more then 1/2 of the replacement costs on repairs.
 

MrAl

Joined Jun 17, 2014
11,389
<no reply here>

Hello again,

You see nothing in that quote because although you quoted my post you did not write any reply. Something went wrong maybe?
Try again and if you have another pic that would help too so we can see the bulging.
 

MrAl

Joined Jun 17, 2014
11,389
This violates the TOS.

https://www.allaboutcircuits.com/user-agreement/

No transformerless supplies.

How did the thread make it this far??

Buy a new supply, Some things are worth messing with.
Hi,

A laptop wall wart is not a transformerless supply. What made you thjink it was?

Virtually ALL wall warts have transformers in them.

What sets the wall warts apart from the transformerless supplies is that the wall warts always provide electrical isolation from the line mains. In fact they must have two physical forms of isolation in order to pass regulations on these things. THere's a certain Class that they fall into and they can only get that class if they have those two forms of isolation.
For example, with a 'regular' non regulated type wall wart they must have both the electrical isolation that comes from a two winding transformer, and also have the two windings separated from each other physically which usually means the two windings (primary, secondary) can not be wound one on top fo the other but must be separated a distance from each other on the core so if the winding is crushed it can still not come into contact with the other winding and thus lose isolation.

A transformerless supply has some direct contact from one lead of the mains line to the output, which meens there is a risk of shock. This is similar to how audio amplifiers in the distant past where often made until some people got shocked and actually died. Now these kinds of supplies are in widespread use as we speak, such as in lamp dimmers, but they are made by manufacturers who know how to circumvent the dangers in the proper way. At the hobby end of the user spectrum, it's probably better not to recommend using one because there are always new people coming into the field who dont realize how bad things can get if they make a mistake. I know real life occurences of such problems but i wont go into detail about that.
 
Top