If you have another P4 compatible power supply handy, just swap it in to test with. If the system starts up, you'll need to replace the Thermaltake.
You're working with just the core parts, right...motherboard, CPU, heatsink, RAM, video card, power supply, PC case speaker and monitor. You're trying to isolate the problem so don't connect anything else up yet.
I like Fortron Source and Sparkle Power power supplies...very clean power on the rails and the ability to go beyond their rated wattage.

Cricket