my power-adapter burnt as i plugged it to wall socket

my power-adapter burnt as i plugged it to wall socket, it was new, the first time plugged to wall, i don't have a multimeter to check the polarity of its wiring, it's a china stuff .. i opened it & found two burnt spots i marked it in red square in the attached picture .. is there a fix for it?
 

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'send it back' wrt me is throw it away, i've got it for cheap from aliexpress with free shipping, it will cost me a lot to send it back .. i couldn't find one locally .. maybe it's better find local electrician to fix it

Can you identify the markings on the failed parts?

Can you obtain them?

If not then can you identify equivalents?

If the markings are not visible then you can determine what the device rating and polarity may be?

Do you have a circuit diagram?

Ask why did they fail in the first place, was it the fault of the PSU or was it something you did?

Can you be sure replacements would not fail again due to some other underlying cause?

This imo is not fixable and it is not even worth wondering whether it can be fixed. It is a dud. Bin it :)
 
i just plugged it into the wall socket and turn the on/off switch of the wall socket to in and imediatly it pop'ed and a little smock .. the burnt part seems to be a transistor has three lead wires .. what is written on it is " 59015 " on the first line and " CF331 " on the second line .. it's very near to 400v 22uf capacitor
 

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So... you already know for sure that it is defective and that it popped... and you still connect it a second time ? And then you ask for further help repairing a cheap defective item of which the repair costs are higher than buying a new one. If you don't have the skills to find out yourself what is defective then don't even think of repairing. Mains connected stuff as well so not for the beginner.

That is all a little dumb.
 
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It's not often I'm negative about doing and attempting repairs on here but this is definitely one of those rare occurrences.

There are probably other failed parts besides those, it is just they are not so obviously damaged.

It's a no hoper I'm sorry to say.
 
From what I see, destroyed part is with side where type is written, so maybe it is possible to repair it.
On printed circuit board is "CBE", not CFE.
What I will do is to replace all the transistors (2 small TO-92 and 1 big on heat sink), also replace optocoupler and check input bridge (4 diodes in package).
On secondary check rectifier diode to be shure it is not shorted.
To repair SMPS is really tricky as Mooly said, if you really want to repair it yourself, try my suggestion.
Good luck
 
There is normally a ferrite core output coil of bad quality connected to Schottky output diodes as the final stage, the primary side is a 13001 or similar switching transistor which induces current in the secondary.
It has most likely popped the transistor as it failed, maybe overloaded.

For a charger or whatever, 50 to 60p UK is the retail price here for this cheap item.

Repairing the coil will be more than that.
Buy a new good quality one.

If you really need an odd voltage, build a 317 based supply with meter.
 
it's better to get a new one, i thought it could be possible just change the burnt transistor with a new one .. before i get rid of it, can i de-solder the other parts for some other uses? like the transformer the resistors the capacitors? or those could be also internally defected/damaged?
 
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Find a known good brand, check the Volt/Ampere ratings and the plug diameters and buy a good one. If the device has digital communication (like many laptops) then one has to buy the original PSU.

* If it is meant for audio and the device does not want more than 15VA like a DAC you could build a linear low loss/low heat/low noise PSU of excellent quality.
 
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ok, i want it to power a sony car receiver at home that requires 12v 5a power input , those are a lot on web-stores and generally are about the same price and cheap with often high rating of reviewers, so when i picked one i had no good luck with it .. i'll try mabe get something better from some better & more honest web-store
 
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That should have been in your first post. Make that a 12V 7.5A (yes it is Volts and Amperes so V and A) SMPS, you want some headroom. If you play loud you may need an open frame SMPS in ventilated casing. Passive of course, fans are for losers.

Or ... solar panels with lead acid batteries if you know how to handle both safely.
 
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