PS
what is the model of the battery charger, maybe we can get a circuit from google.

Hi Dave, first picture is whats on the side of the charger.



I've took four photos of the circuit board, two of the front (1&2), & two of the back (3&4).









If you want anymore detailed photos, it's not a problem.

Thanks,

SS.

 

Perfect, looks like its the opto coupler underneath the pulse transformer(5 pin device black) middle photo right side, it needs changing with the lm431, the resistor is possibly a 220 to 470 ohms.


Its possible the mains has gone high voltage, blown the black capacitor, blown the U3842 chip, the opto, and the LM431.

 

Agreed that the resistor, 431 IC, and six pin opto will all be dead.

Also the primary cause was probably C8 going high ESR.

C8 is the electro cap near the 8pin IC, you can see electrolyte corrosion coming from underneath it.

The big 150uF 400v cap is bulged but is probably ok, I have tested many bulged ones and they test fine for capacitance and ESR. The 400v cap is very rarely the cause of SMPS failure.

So many parts are blown, I would call it uneconomic to repair. That is a heck of a lot of work and some special order parts.

You can buy a new one on ebay for probably the same as the parts costs and postage. And save all that work, save the risk it might still be a bad SMPS transformer (or dead 8pin SMPS IC), AND get a new supply with 12 month warranty.

 

This is a circuit of a 240vac to 24v dc SMPS to give you some idea how they look using a similar opto feed back. I would start with any dodgy electrolytics & parts RB suggested if you are realy keen.

 

So many parts are blown, I would call it uneconomic to repair.

Yes...looks like its opening a can of worms, & theirs no guarantee that it will be fixed after all the advice given is accomplished.

Think Id be better off buying a new one.

Thanks to all who have contributed to my thread for your time & effort helping a complete noob to circuits etc .

Much Appreciated,

SS.