I shorted the output on my generic 12V/24V 10A charger, so no o/p. it has a capacitor input to this chip. whilst handling the board my hand contacted the area near the chip and recieved a shock discharge, so I conclude this chip has blown, as it failed to discharge the capacitor into the transformer. apparently these are obsolete stock, so getting one might be hard now. I see a number of similar cheap chargers on ebay, prob all using the same chip. only one model has short cct protection, but not mine. Patrick's Law==Murphy was an optimist! Anyone agree with my diagnosis, and able to source me one only? There is another 3 pin power chip on the board, prob a dual diode [judging by the small heatsink] to rectify the output. I can't read it in situ-my vision is too poor. I may test it with a meter, but I'll delay extracting it.

edit #1
2nd chip extracted--2 outer terminals common, center terminal to o/p. Prob a pr of diodes sharing the load. dmm says center pin connected to case, polarised between center pin/case [-ve] and both outer terminals.

I DO wish chip numbers were contrast coloured for visibility. Black on Black ==invisible IME. Surely it's worth the small cost? Most techs would end up short sighted from close-up focusing, so I think it's worth the goodwill, or are we expendable too? I cannot read the impressions, and have no way of readily improving my view.

Edit #2
anyone able to recommend a 2 or 3 pin device int a to92 type case which will substitute for the dual diode and provide thermal/overload protection without further mod? Would be good to have.

Edit #3
confirmed-it is a dual diode with cathodes common according to inscription. Looks a bit crude/foreign writing-could be dodgy/cheap part.

 

If you can take photos of the items and post them it will help you better.

Here is a dual diode in a T0220 package comon Cathode.

http://cpc.farnell.com/on-semiconductor/mur1660ctg/diode-ultra-fast-16a-600v/dp/SC07385

 

If you can take photos of the items and post them it will help you better.

Here is a dual diode in a T0220 package comon Cathode.

http://cpc.farnell.com/on-semiconductor/mur1660ctg/diode-ultra-fast-16a-600v/dp/SC07385

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Seems good, thks. yes I had the case wrong. Still don't have the viper chip tho'.Farnell are called Element14 these days in Oz.