Alternate Solder point:
http://www.piratesrus.org/X-ecuter/Troubleshooting solder points:
http://www.mrmodchip.../testpoints.htmDO NOT do either of these!
Your Xbox is working FINE, you merely have a cold solder joint (which the Brits call a "dry" solder joint).
The above two proceedures will probably result in you obtaining a non working Xbox since you do not seem to know what you are doing.
Why are you so insistant on taking the harder path?
What we are telling you to do is easy and painless!
Just TOUCH the solder points for 2-3 seconds until you see the solder melt.
It will get much more shiny, when it does so. Hold for an additional second or two and remove the iron.
Simple, nothing to it.
AVOID the one wire to the motherboard. If you pull this you will be SOL!
Fixing it is VERY difficult.