I bought a Xbox 360 from the us and when it arrived it had a 110v psu that subsequently i blew up !
i live in South Africa witch is a 220 v country .
so i googled a way to fix it and it came with a item on ebay witch would have cost another $10
that i don't have . and i would have to wait for a long time to get it . i then found another diy one . i will post a link . i then took that plan and modded it to work with my 300w power supply .
here is a link to that site : http://www.360-hq.com/xbox-tutorials-20.html
Step 1: The Schematic
I take no responsibility for damage done if it does not work .
the wires are colour coded in my picture . cut off all the other wires . i left mine about 5 cm long so i could use them to form the shape .once i had it all soldered together and tested i covered it in heat shrink and hot glue.
Step 2: Finished
Here is a link to the video of me powering up