Sadly my christmas led string was defective when i have put all the illumination on my christmas tree, i decide to investigate... i found easily the cable was broken at the plug entry, unfortunatly this plug is moulded.. The only solution was to open this molded connector to remove the pins and create a new plastic plug to fit in the transformer.
Here is my led string : http://s.click.aliexpress.com/e/cehN8vgM
Only the transformer is quite different but if you own a 11mm connector it will work....
You need to extract the old pins (and his plastic holder) from the broken connector in order to fit in the new design.
Some glue maybe necessary to lock safely the differents parts together.
All the parts has been optimized to be printed verticaly without efforts.
Happy printing !