PowerEdge 1900 power issue

Hi,

I am an IT consultant working for a client with a Dell PowerEdge 1900 server.  Two mondays ago, my client called me about their PE1900 server with no power.  We tried a few things to try to power it up.  I have since had the client bring the PE1900 server hardware to my office and I still cannot power it up.  

Normally, when I press the power button after taking the front cover off I can hear the chassis fans are making noise and it will show on the monitor the POST BIOS message and begins to boot up.

However, now it doesn't power up at all.  Now, the LED on the power button does lit up with green color and the LED at the back lit up in blue.  So I know it's getting power from the power supply.  However, pressing the power button does not seem to get the server hardware to power up.

Any help will be greatly appreciated.