Computer build mystery please help I'm sure you know the answer?

First thing is check all of your power supply plugs. Make sure they are fully in on the board. Make sure the CPU power is using the 8 pin connector and is plugged in all the way. Check your jumpers for the power button, reset button, HD LED and Power LED. The little arrow on them is positive. If after checking all this and it still does not start, take out the GPU and Wireless card, unplug the hard drive from the motherboard and power supply, do the same with the DVD drive. Leave 1 ram stick in the A1 ram slot and try to boot. If it boots, go though the process of adding components one at a time. Ram A1 and B1 slots, Hard Drive, DVD, Wireless card then GPU in this order. If it wont boot after adding a component then that component may be the problem. If you get all the way to the GPU and then it wont boot, it is most likely the power supply. I have had many problems with Ultra Power supplys over the years. They are quite flaky. OCZ and Thermaltake PowerSuppliess are good brands to use. I could almost say with mostcertainlyy that this will be the problem. But you should check everything out.