Broken off board charger

[Its me]

My off board charger stoped working.
So, I opened it and discover that some components are fried

I have 2 pictures of it.
One of the complete board with charge leads
and one of the fried place.
(in the red oval)

I hope that there will be somebody who has also a picture of it for me.
And of course that I can read the tekst on it.
It will be a big resistor and at least 2 SMD components.
I think a transistor (with the little hole in it) and 1 ore maybe 2 resistors.

And also, not unimportant, anyone an idea how it is possible?
Is it right, that it will fried if you switch the charger on, without any batteries connected?

I will appreciate your help,
Thanks

[Isidore]

Interesting! The chargers in the Gen 1 Segways used to fry themselves and I spent a lot of time trying to get a circuit diagram to repair one of those. The original manufacturer went bust and was bought out by another company and they were refusing to give out the circuit diagram because they said that the design was Segway's copyright. The problem you have is that you probably cannot read the component types/ values on the fried parts except for the large resistor. Are both channels not working or just one? I don't think that having the unit on but not connected would do it any harm. Does the manufacturer have his name anywhere on the circuit board?

[Isidore]

Circuit made by Magnetek- have you thought of contacting them?

[Its me]

Somewhere on segwaychat I read also something about an broken off board charger and indeed its made by Magnetek. It should be in Italy but I also read its in USA But what ever where it is they will not tell enything about it, I also read. I didnt try to concact them becouse what you said and also in the other thread.From one component I can read it but not from the others. I realy dont know if one is working but I think not. I dont try to plug it in again, Im scared that I get another little boom. I also thought that it would not harm when the leads are not connectet to a battery. But do you have an off board charger to take a picture of?

[dgbint]

Hi

This is MAINS level switching power supply.
This is a complicated circuit, and has very high voltage levels, especially in Europe.
You can KILL yourself if you do not know what you are doing.

This type of circuit should only be tampered with by an experienced electrical technician, with appropriate equipment.

If you do not meet this description, do not play with it.

Michael

[Isidore]

Originally Posted by Its me

Somewhere on segwaychat I read also something about an broken off board charger and indeed its made by Magnetek. It should be in Italy but I also read its in USA But what ever where it is they will not tell enything about it, I also read. I didnt try to concact them becouse what you said and also in the other thread.From one component I can read it but not from the others. I realy dont know if one is working but I think not. I dont try to plug it in again, Im scared that I get another little boom. I also thought that it would not harm when the leads are not connectet to a battery. But do you have an off board charger to take a picture of?

I will have a look and try to send you the image- The original manufacturer was Italian and went bust. From the location of the components it is in the mains voltage part of the device. Clearly you need some experience at soldering semi conductor devices but if you can get the components it's worth a try as otherwise you just have an expensive door stop. Be careful and if you get it going test the output is what you should expect!

[Its me]

Originally Posted by dgbint

Hi

This is MAINS level switching power supply.
This is a complicated circuit, and has very high voltage levels, especially in Europe.
You can KILL yourself if you do not know what you are doing.

This type of circuit should only be tampered with by an experienced electrical technician, with appropriate equipment.

If you do not meet this description, do not play with it.

Michael

Hi Michael,

thanks for your concern, but I know that it could be dangarous.
But do you know someting of these chargers at all?

Thanks

[Its me]

Originally Posted by Isidore

I will have a look and try to send you the image- The original manufacturer was Italian and went bust. From the location of the components it is in the mains voltage part of the device. Clearly you need some experience at soldering semi conductor devices but if you can get the components it's worth a try as otherwise you just have an expensive door stop. Be careful and if you get it going test the output is what you should expect!

That would be nice
But if you take a good look, you can see that it will be right after the high voltage. But of course it would be also dangarous becouse its close to the high voltage. I hope I can fix it, that would be nice for this price
But what was the problem that its fried, thats the question....

[Thomas]

Resistor R2 is brown, red, silver, gold = 0.12 Ohms 5%.
The top one of the four SMD components has no printing on it, but has three pins so it should be a transistor.
Next to it are two 4.7 Ohm resistors.
The part at the bottom is a 470 Ohm resistor.

[Its me]

Hi Thomas,

thanks.
But on the transistor is printed 5Bs 28
There are another two of these.
And the last is indeed 470 ohm.
For the other 2, I hope you have right becouse it's not readable.

Do you have any notion how this is possible?