LaCrosse BC900 got fried by using wrong transformer

[Tycho]

Any electric engineers or enthusiastic out there?
I nstead of plugging the regular 3V/4A on the charger, I hit it with 12V/1,5A and it sure killed it.

If you know the processor is fried, thereäs really nothing to about that, but if it killed any of the diodes (I have chekced few) or resistors, could you point me closer to the source.

Or if anyone would know were to obtain a repair manual for that unit =)

 

[Papuga]

I have never taken my BC900 apart, so I cannot speak with authority as to the circuitry inside it, but I have had a similar situation with one of my daughter's toys. (if the plug fits, it must be the right one, right? - Not )

Depending upon the designers original idea, and how it may have been modified from original concept to final production, your problem may be very easy to fix or it can be a total loss.

If it was designed properly, the most likely candidate for failure from this type of error would be one or more current limiting resistors, possibly one or more diodes or a voltage regulator. Given how everything today is made of surface mount devices, my best guess would be one or more limiting resistors have given their life due to the higher input voltage/current. If the engineers that designed the charger were faced with trimming costs, such protection circuits would have been employed in the wall wart itself and the regulated voltage fed directly to the main board. If this is the case, microprocessors don't like voltages above their nominal ratings and most likely the expensive processor has protected the low cost passive components by giving its life first.

Personally, I would open the charger to see exactly where the smoke trails are, I would say that it is already dead, so, if you open it up, you cannot possibly cause anymore damage that has already been done.

Good luck.

 

[berserkk]

sorry for reviving this old thread, but i just did the exact same thing.
did you manage to fix yours?
else i'll have to downgrade to a bc-700 (cheapest alternative..)