No power to computer tower, power sup...

Sounds like possibly a failed power supply. If you take yours to a reliable local tech, they can load test it to be sure, and probably provide you with a new one for about $30.00.
Otherwise, please see this article to troubleshoot the problem.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!