Dell Studio XPS 435mt

I have a Dell XPS 435mt, and it has been working until one day I shut it down and tried to turn it back on. All I had was a flashing orange power light, but it wasn't a normal flash. It was more of an unhealthy constant flash. When I pressed the power button, it made the fan spin for like .5 seconds, and then nothing. If you hold the power button it he fans "pulse" on and off. I have tried reseating the ram, took out the graphics card, took out the CMOS battery and held the power button, all ending with me wondering what could have possibly happened. I tested the power supply with a paper clip and it worked.

If anyone can help, please let me know. Thanks in advance!

                                                                          Ethan